Aaj kal wo cheezen bik rhi h jiski marketing achhi hoti h.the most common thing is that students r nt able to decide what is best for them.ur content is at par excellence.but very underrated.
Alternate for question Chennai - Bangalore Speed ( Train 1)= d/4, Speed ( Train 2 ) = {d/(7/2)}= 2d/7 ---- Given Total distance travelled will add up to 'd' d= (d/4)*t + (2d/7)*(t-2) - Equation 1 t= 44/15 hrs= 2 hrs 56 mins train1 = 5 AM + 2hrs 56 mins = 7 AM 56 mins train 2 = 7 AM + (t-2)= 7 AM + (2hr 56 mins - 2 hrs ) = 7 AM 56 mins Only that one equation will do.
@@MadaraUchiha-u3c in 4th question to convert km/hr to m/s, to convert km to m multiply by 1000 and to convert hr to sec we need to divide by 60 twice one to convert to minute and again by 60 to convert to seconds i.e. 1000/3600=5/18 so directly multiplying it by 5/18 converts km/hr to m/s and multiplying by 18/5 converts m/s to km/hr. Hope this helps
Also, if the cyclist is further ahead from the bridge, are we to assume that there is no gap between the train and the cyclist? In other words, the train starts off directly behind the cyclist when it completely passes him in 20 seconds.
Sir here they said that the longer train crosses the flag on the smaller train,not the length of the train from the flag's position.So here shouldn't we consider the flag as moving object with out any length?Please clear the confusion.
In the first question is it necessary to take the 100 of 2nd train? It is same as one train passing a person in another train in opp dir, where we need to take only the length of first train and rel speed. Here flag pole is also like a person sitting stationary.
Exactly this is what I think. It is just like a train crossing a pole. The relative distance here should have been 300 instead of 400. But here I think the question was a bit confusing and the language was not much clear, if we take the given approach here to be the correct one, then the question should be framed like this: "The longer train after facing the smaller train crossed the flag on the smaller train in 8s."
Just assume you are at the rear end of the 1st train. To get to the flag, you will first need to cover the length of the train and then half of the other train's length. That's why it's (300+100) m = 400 m
The last question... are we to assume that there is no gap between the cyclist and the bridge? A little clarity would have made a difference. Other than that minor gripe, great job.
you have to assume if train crossed bridge completely and then it crosses cyclist, then the distance between bridge and cyclist would be equal to the length of the train
Yes that assumption needs to be made. Its a logical and rational assumption so I don't think the question needs to clarify as such. But would be helpful if given explicitly.
in the second question, if the question was "At what time do they meet each other (instead of cross each other)" what would be the ans? Someone pls respond.
No , in the question they have asked what is the speed had both the trains been running in the same direction , this is where cat tricks you , read the question properly
I made a wrong decision by paying 70k for career launcher classes ,they are one of the worst institutes with good marketing team , recently i went through this channel and for anyone who thinks onpy paid videos can get you through cat exam ,you are wrong ,through this channel i have learned more then i could have ever in cl
Sir in the second question (the one with Indian flag) - what if when calculating same direction part, we take starting point of both trains as same? In that case it will be 30 seconds. How to identify the case whether same starting point is there or not, as in questions it is often not mentioned…
Sir could you please explain why in the Chennai Bangalore question we are taking 14km as the distance to calculate the time taken for the two trains to cross each other? Should it not be 14+28 since we need to consider the length of both the trains?
We know that 1 km= 1000 metres and 1 second=1÷3600 hours. Simply in this question to convert 36 km/h into m/s we can write 36×1000÷3600 by solving it we get 36×5/18
36km = 36000 meters. 1 hour = 60 mins = 3600 secs. Divide 36000/3600 then you'll get 10 meters/sec. The question was, train first crosses the bridge and then it bypass the cycle but sir took both at the same time. By using the speed and the passing time of train we must calculate the length of the bridge. So, if train can cross a moving cycle with the speed of 2.5m/s by 20 secs and a bridge (stationery) in 48 secs then what would be the length of the bridge? So here's the answer, if a train can move 10m/s then it obviously crosses 480 meters in 48secs. Here we don't know the length of both train & bridge, as bridge is stationery we must follow (X+Y) method. Let's consider length of train = X and length of bridge = Y, and time taken is 48secs. So it goes like this, T= X+Y/speed, 48= X+Y/10 and by replacing X+Y we get X+Y = 48×10, therefore X+Y= 480 meters. Then to calculate length of bridge you must deduct length of train from 480 meters. So, calculate speed of cycle now, that's 2.5m/sec as both train and cycle are moving in same direction we must follow (X-Y) method. Consider X as length of train, so Time= X/speed of train - speed of cycle. That give rise to 20secs= X/10-2.5, that is equal to X= 7.5×20, therefore X= 150. If X+Y=480 but X= 150 then Y= 480-150, therefore Y= 330 (length of the bridge)
the flag is on the roof of the train. so total distance is 300+100=400m time is 8 sec. speed comes out 50m/s. this is speed of train 1+2. train 1 is 30m/s, so train 2 is 50-30= 20m/s
forget 2nd train what if a flag is moving with 'x' speed then we cant take 100 so that part is wrong it must be 8=(300)/(30+x), solving this we'll get speed of shorter train and so further calcn will be done@@Sherrrrrrrrrrrrrr
Sir you are saying its very easy to assume Distance as a LCM of both the times but you have not mentioned the REASON BEHIND ..CONCEPT BEHIND this LOGIC,,not able to understand
someone please explain me this, @17:48 L1+ L2 = 480m(where L1 is train's length and L2 is bridge length) but he did not include the distance of the man(becoz the train took another 20 sec to cross him, so he must be at some distance) from the bridge in this 480m and now @19:23 he is deducting the distance of the man from the bridge from that 480m. HOW ? the total distance the train covered to cross the man from the train's initial point must be 480+L3(distance of man from bridge), then he can deduct 150 from that. Please clear my doubt @rodha
I guess the framing of question is a bit confusing, but here the cyclist's info(point object) is given for us to calculate the length of the train(Question says it then crosses a cyclist, which means that happened after the bridge) so 150 here is the length of the train
no its not in the sane direction..in the second question train coming from chennai to bangalore and the other train coming from bangalore to chennai..so they are in the opposite direction
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Aaj kal wo cheezen bik rhi h jiski marketing achhi hoti h.the most common thing is that students r nt able to decide what is best for them.ur content is at par excellence.but very underrated.
Plz share among your frnds :)
who said it's underrated. And even if it is, it's for those who are interested. We will definitely have an advantage over others
Lmao he's not underrated. Probably would have been back 2 years ago, but now he's a headache for all coaching institutes
Saying Rodha underrated is equivalent to saying Sachin Sir not a great cricketer😂
Alternate for question Chennai - Bangalore
Speed ( Train 1)= d/4, Speed ( Train 2 ) = {d/(7/2)}= 2d/7 ---- Given
Total distance travelled will add up to 'd'
d= (d/4)*t + (2d/7)*(t-2) - Equation 1
t= 44/15 hrs= 2 hrs 56 mins
train1 = 5 AM + 2hrs 56 mins = 7 AM 56 mins
train 2 = 7 AM + (t-2)= 7 AM + (2hr 56 mins - 2 hrs ) = 7 AM 56 mins
Only that one equation will do.
can you please explain why is time considered as (t-2) for the second train ?
@@ananyaa9 coz 1st train is leaving at 5am and 2nd train starts at 7am so time gap of 2 hours that's why (t-2). In order to equate time
hey can you explain in 4th Q how it comes in 5/18....? plus
@@MadaraUchiha-u3c in 4th question to convert km/hr to m/s, to convert km to m multiply by 1000 and to convert hr to sec we need to divide by 60 twice one to convert to minute and again by 60 to convert to seconds i.e. 1000/3600=5/18 so directly multiplying it by 5/18 converts km/hr to m/s and multiplying by 18/5 converts m/s to km/hr.
Hope this helps
Bhai sir ka answer aur aapka answer karne may Kum time kisme lagta hai
yaaaaar, ravi sir i genuinely respect you, yeh topic class me 1% bhi smjh nahi aaya tha, aur ab saare questions solve hogye pause krke #fan
Literally The Besttt teacher I ever have studied from ✨
only because of you and your videos , I am sure that I will definitely clear CAT : )
WHICH COLLEGE DID YOU OPT SIR?
Did u clear cat???
Did u clear sir?
@@anmolmaan7008 he's in BML munjal
did you clear cat????????
@@anmolmaan7008
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The Besttt teacher I ever have studied from ✨
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Also, if the cyclist is further ahead from the bridge, are we to assume that there is no gap between the train and the cyclist? In other words, the train starts off directly behind the cyclist when it completely passes him in 20 seconds.
yes
Sir here they said that the longer train crosses the flag on the smaller train,not the length of the train from the flag's position.So here shouldn't we consider the flag as moving object with out any length?Please clear the confusion.
Same problem bro ✋
watch the first part again and get the concept of relative speed
In the first question is it necessary to take the 100 of 2nd train?
It is same as one train passing a person in another train in opp dir, where we need to take only the length of first train and rel speed. Here flag pole is also like a person sitting stationary.
Exactly this is what I think. It is just like a train crossing a pole. The relative distance here should have been 300 instead of 400. But here I think the question was a bit confusing and the language was not much clear, if we take the given approach here to be the correct one, then the question should be framed like this: "The longer train after facing the smaller train crossed the flag on the smaller train in 8s."
I have the same doubt, I think we need not take half the length of smaller train.
Just assume you are at the rear end of the 1st train. To get to the flag, you will first need to cover the length of the train and then half of the other train's length. That's why it's (300+100) m = 400 m
Yes, I agree . Its written that the train crosses the flag in 8s . so the distance should be 300m .
@@shomailafatima2586 Yes exactly
Thank u soooooo much sir for explaining complex concepts again and again 🙏🙏🙏🙏🙏🙏
it looks so easy when u solve ques .....but when im trying it seems to be difficlt..
The last question... are we to assume that there is no gap between the cyclist and the bridge? A little clarity would have made a difference. Other than that minor gripe, great job.
you have to assume if train crossed bridge completely and then it crosses cyclist, then the distance between bridge and cyclist would be equal to the length of the train
cyclist is also moving with a speed along with train so distance travel by train to completely cross the cyclist would be length of the train
Yes that assumption needs to be made. Its a logical and rational assumption so I don't think the question needs to clarify as such. But would be helpful if given explicitly.
in the second question, if the question was "At what time do they meet each other (instead of cross each other)" what would be the ans? Someone pls respond.
Done 👍🏻
24 September 2024
Sir you are awesome
At 4.46 the relative speed should be 30+20 as they are moving in opposite direction
No , in the question they have asked what is the speed had both the trains been running in the same direction , this is where cat tricks you , read the question properly
sir , in qus chennai and bangalore , if we assume speed 7 and 8, hereby we should need to take distance lcm of 7 and 8 so answer of that qus is9:48
I made a wrong decision by paying 70k for career launcher classes ,they are one of the worst institutes with good marketing team , recently i went through this channel and for anyone who thinks onpy paid videos can get you through cat exam ,you are wrong ,through this channel i have learned more then i could have ever in cl
same here bro
Same bro paid 75k on ims
what's your CAT percentile?
🔵⚪ Great fruitful session ⚪🔵
10:44 56mins is not the answer, 7:56AM is the answer
Sir in the second question (the one with Indian flag) - what if when calculating same direction part, we take starting point of both trains as same? In that case it will be 30 seconds. How to identify the case whether same starting point is there or not, as in questions it is often not mentioned…
It's mentioned in question that another train is coming from opposite direction
Sir could you please explain why in the Chennai Bangalore question we are taking 14km as the distance to calculate the time taken for the two trains to cross each other? Should it not be 14+28 since we need to consider the length of both the trains?
You don't want to ingore every steps I don't understand in 16.00 how 36× 5/18 is came
We know that 1 km= 1000 metres and 1 second=1÷3600 hours. Simply in this question to convert 36 km/h into m/s we can write 36×1000÷3600 by solving it we get 36×5/18
Can anyone explain me at 9:44 why sir is taking the distance as 14 instead of total distance which would be 14+14=28
We have to take distance from 7am.
7am - 5am = 2hr
Dis. = speed x time
=7km/h x 2hr = 14km
28km -14km = 14km
Sir at 3:08 Flag's distance should not be under consideration
can someone please explain to me in which case do we take lcm???
great sir
Sir plzzz explain the reason behind assuming distance as LCM of given speed or given time
Do watch his initial videos to get the LCm method of Time Speed
@@arnabsaha2021 which videos? Can you please provide link
8s = 300+1000/30+x = 20?😢
there is something wrong with the train and cycle question right ?
Why is the cycle's length considered negligible?
36km = 36000 meters. 1 hour = 60 mins = 3600 secs. Divide 36000/3600 then you'll get 10 meters/sec. The question was, train first crosses the bridge and then it bypass the cycle but sir took both at the same time. By using the speed and the passing time of train we must calculate the length of the bridge. So, if train can cross a moving cycle with the speed of 2.5m/s by 20 secs and a bridge (stationery) in 48 secs then what would be the length of the bridge? So here's the answer, if a train can move 10m/s then it obviously crosses 480 meters in 48secs. Here we don't know the length of both train & bridge, as bridge is stationery we must follow (X+Y) method. Let's consider length of train = X and length of bridge = Y, and time taken is 48secs. So it goes like this, T= X+Y/speed, 48= X+Y/10 and by replacing X+Y we get X+Y = 48×10, therefore X+Y= 480 meters. Then to calculate length of bridge you must deduct length of train from 480 meters. So, calculate speed of cycle now, that's 2.5m/sec as both train and cycle are moving in same direction we must follow (X-Y) method. Consider X as length of train, so Time= X/speed of train - speed of cycle. That give rise to 20secs= X/10-2.5, that is equal to X= 7.5×20, therefore X= 150. If X+Y=480 but X= 150 then Y= 480-150, therefore Y= 330 (length of the bridge)
It give rises to X= 7.5× 20 that means X= 150, if X+Y=480, then Y=480-150, therefore Y=330 (length of the bridge)
Are these videos still relevant for 2023
Maths Koi current affairs h kya jo badal jayegi.... ?? It would be same always
How to get 8s=300+100/30+x=20
I've the same doubt!!! How?
By cross multiplication
8(30 +x) = 300+100
240 +8x =400
8x=400-240
8x=160
X=160/8
X=20.
Can anyone explain at 3:25 how it came to x= 20 m/s?
the flag is on the roof of the train. so total distance is 300+100=400m time is 8 sec. speed comes out 50m/s. this is speed of train 1+2. train 1 is 30m/s, so train 2 is 50-30= 20m/s
forget 2nd train what if a flag is moving with 'x' speed then we cant take 100 so that part is wrong it must be 8=(300)/(30+x), solving this we'll get speed of shorter train and so further calcn will be done@@Sherrrrrrrrrrrrrr
Sir you are saying its very easy to assume Distance as a LCM of both the times but you have not mentioned the REASON BEHIND ..CONCEPT BEHIND this LOGIC,,not able to understand
to get speed as an integer.
for easy calculation.
Edit* sir has already mentioned in one of the videos
@@junedahmed8436 which video? Pls send link
Thank you sir
How calculate LCM ??
Couldn't find the first video of relative speed so basics is not clear 😮💨😖
It's in sequence
@@Rodha found it sir! 😃😄😄
someone please explain me this, @17:48 L1+ L2 = 480m(where L1 is train's length and L2 is bridge length) but he did not include the distance of the man(becoz the train took another 20 sec to cross him, so he must be at some distance) from the bridge in this 480m and now @19:23 he is deducting the distance of the man from the bridge from that 480m. HOW ?
the total distance the train covered to cross the man from the train's initial point must be 480+L3(distance of man from bridge), then he can deduct 150 from that.
Please clear my doubt @rodha
I guess the framing of question is a bit confusing, but here the cyclist's info(point object) is given for us to calculate the length of the train(Question says it then crosses a cyclist, which means that happened after the bridge) so 150 here is the length of the train
Legend
X=20sec kaise aaya sir first question me
8 = 400/ 30+ x
In 1st question consider half of the train is red coloured in place of flag
😭thankyou sir
Compare an academic like him to a Salesman like CatKing.
I rest my case.
Thankyou sir
Can anyone explain why im second question we added speeds in Relative Speed, Its in same direction so we should substtract na...🙄
no its not in the sane direction..in the second question train coming from chennai to bangalore and the other train coming from bangalore to chennai..so they are in the opposite direction