Mate .. rs Agarwal books are not good for competitive exam preparation. It's good for academics , you can prefer Pearson,hc,verma,rd Sharma .for exams like NTSE / KVPY
Another Solution :: Take a number say p square it p*p subtract 1 from p*p now divide by 24 if it divided its prime. That's it. Formula is p is prime if [(p*p)-1] ➗ 24=0 then p is a prime number. Only Exception cases where p is 2 & 3.
For example the last number 627 is not only divisible by 3, but by 11 and 19 too. So the prime factor of 627 are 3×11×19 and therefore his submultiply are: 1,3,11,19,33,57,209 & 627. 👍💪🤙🤦♂️🇪🇺
Sir pls tell me how it will work in 57 as 8²>57 and 2,3,5,7 can't divide 57 but 19 can so here the shortcut isn't working or something in process is wrong ?
Thanks for making this video. My daughter's homework became easier. But this method is effective as long as step 2 is a small number. When i tried tjis method on 677, i had to find a number square above 677. Kids in grade 6 need a calculator for this, which is prohibited. Lets hope my daughter doesnt get a large number like 677 on a test.
As I took a no. 77 to test in your method as it is a prime or not Following this way above 77 Square no 9(9)=81 (it is a no. Above 77 ,,,as considering under the no. 9 values (2,3,5,7) I found that 7 is a divisible of 77 ...so like the way you told that (Is it could be proved that 77 is a Prime no.) Please reply as soon as I need your pleasure of thought weather my substitution is right or wrong?
No it is clearly not Prime. 7 is a prime number below 9 and divide 77 to produce a quotient of 11 and remainder is 0 .Sir's method is absolutely correct
No I think you got that wrong. It is only for divisibility by 3 that we test like that. For example to check whether 129 is divisible by 3 or not, we do 1+2+9=12. Since 12 is divisible by 3 so 129 is also divisible by 3. This rule is only applicable in case of divisibility test by 3. For other numbers it is different.
For 563 Check the next perfect square i.e, 24²=576 So, all the prime nos. Below 24 are 2, 3, 5, 7, 11, 13, 17, 19, 23 Now check if 563 is divisible by any of them. You will find it is not divisible by any of them. So, 563 is prime number.
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Agarawal peoples are legend that's why im using Dr. R.S Agarwal's Elementry Book for competitive exams, it's perfect helping me alot.
Agreed 😀
Improving your English will help you in becoming a civil servant.
People not peoples
@@ananyasingh5809 lol you are really gonna call out somebody because of their English? Pathetic behaviour 💀 remember English is just a language :)
Mate .. rs Agarwal books are not good for competitive exam preparation. It's good for academics , you can prefer Pearson,hc,verma,rd Sharma .for exams like NTSE / KVPY
Another Solution :: Take a number say p square it p*p subtract 1 from p*p now divide by 24 if it divided its prime. That's it. Formula is p is prime if [(p*p)-1] ➗ 24=0 then p is a prime number. Only Exception cases where p is 2 & 3.
For example??
He didn't do any example😢
For example the last number 627 is not only divisible by 3, but by 11 and 19 too. So the prime factor of 627 are 3×11×19 and therefore his submultiply are: 1,3,11,19,33,57,209 & 627. 👍💪🤙🤦♂️🇪🇺
Close perfect square rule:- it's useful upto 4 digit. For bigger no. We confuse and more time. 2- 6n+1, 6n--1 rule has been proven to be false.
You are wrong!! If I want that I believe to you, make me 1 example!! 🤷♂️
Example: 25= 6×4+1, 49= 6×8+1 etc
Thanks sir, it helps my 9 years old daughter to clear her concepts.
@Sawan Challani , 319 is in the form '6n+-1' i.e. 319=6*53+1, it means it may be a prime number ⁉️
319
Best video i have seen so far for prime numbers
Hi .. lam 60 years old now
I wich the know you 40 years befor
Thanks alot
Sir can you make a video for more larger number becz it is in our 10th ncert syllabus sir if you do it it will be very kind of yours
Sharab bahut behtarin Ho Mujhe aapane acche se Sikha Diya Prime kya hai composite kya hai thank you you sir thank you so much☺☺
sir you are excellent
this is my second time i am watching your video
i just understood that you are an exllent teacher
Amazing!
@@cqqp No wayy Big Fan
Amazing method to check a number whether its prime or composite👍
Thank you for this useful trick 👍
I saw this method and now i am in a curious way to like this hard sums thanks Mr Agarwal
What a easy trick sir very helpful 😊😊
Thanks! Sir.
Thankyou so much sir. With your help and guidance, I am able to solve these type of questions.
This is best vedio for understanding the prime numbers
It is Last night , before exam i was seeing this video right now. Sir you had explained very well thanks sir
Fantastic method sir
Thanks sir you are great sir
Sit thank u very much sir🙏
This method is fabulous , i saw so many videos but mujh end me aa hi nhi rha tha .thank you sir
This approach is not applicable to certain numbers like 143, 121.
sir I'm in 6th grade and ncert chapter 3 is a headache to check this method helps a lot
what an amazing method, I never heard of it
Sir pls tell me how it will work in 57 as 8²>57 and 2,3,5,7 can't divide 57 but 19 can so here the shortcut isn't working or something in process is wrong ?
Actually 57 is divisible by 3......
@@march_mellow3 lol big mistake 😂
@@march_mellow3 😑thanks
Incredible sir🙏🙏🙏🙏
You are great sir
You make learning fun instead of boring . I found maths hard but you made it easy 👍👍👍👍👍
Thanks. Do share the links with your WhatsApp groups and contacts
I surely will sir, this will help them a lot
Thnk u sir....for explng the concept in supr way
Sir why not the largest perfect square less than equal
Thanks for making this video. My daughter's homework became easier. But this method is effective as long as step 2 is a small number. When i tried tjis method on 677, i had to find a number square above 677. Kids in grade 6 need a calculator for this, which is prohibited. Lets hope my daughter doesnt get a large number like 677 on a test.
Ek number sir !
Over Powered
well done sir....excellent job
It's smaller number. Say for larger number more than 5 digits.
This is so easy now thank you so much
Great method sir...really it helped a lot
Sir really big thing.its very useful
Explain prime no
I gave a subscribe because of this video
Your method helped me, thank you
Thank you sir
Sir Teach Us in Hindi Many Students Dont understand English sharply But Not Me Many students
A lots thanks sir for helping me with trick👍️💓
Thank you sir
Really helpfull
sir saviour ho aap 🙏
Nice video
Thank you sir. You are the best
Nice video for my final exam tomorrow
Nic teaching sir 👌
Thankyou so much sir
Aapki video bahut achi Hai ase hi daliye
You're a fantastic teacher: knowledgable, clear, thorough, and kind. Thank you so much for your help! Subbed :)
I have not seen any teacher useing simple ways to explain
How about a bigger no like of 6 digits.... We cannot find out a sqrt so easily for that and mention all the prime numbers before it..
Awesome sir
Than u so much 💚
Sir ye rule 25 ke liye check kiye to 5 ka square hai to 2,3 se check karna tha to in dono se 25 nhi divide hua but 25 to prime number nhi hai
Thanks you sir
Thank you, clear and easy to understand video.
Very nice explanation sir
Thank you sir .it helped alot.
Thank you so much 👍
Thank you for tech this technic
This method is useful for any no
I mean 4 digit 5 digit etc
Please reply 🙏❤
Wow!! This algorithm looks like the easiest to implement in Assembly language.
👌👌👌
best video so far, thankyou
Superb 🎉😊
Ya toh aise sawal mere galat hote the ya inhe chhodna padta tha..... Thank u 🙏🙏
sir u are fantastic
Very useful class sir
Wow 🤩 easiest method
But by using this trick "2017" should be composite no. Because the square root of 45 Is 2025 ..
But 2017 is prime number ..
Sir, thank you for explaining.
Thanks for clarifying as a new comer...🙏🙏🙏🙏🙏
Thank you. Needed this trick before my discrete math midterm. You're a lifesaver
Same
Execellent explanation sir
Thank u sir..it was very helpful
Thank you sir 🙏🙏👍👍
Very helpful
Thank u sir.....🙏
Veru nice sir 😮
453 is not a prime because 4+5+3 =12 and 12 is divisible by 3
If you mentally group the numbers, it's easy to see that 453 is composite. 45 is divisible by 3, and 3 is divisible by 3..
👑 thank you king
As I took a no. 77 to test in your method as it is a prime or not
Following this way above 77 Square no 9(9)=81 (it is a no. Above 77 ,,,as considering under the no. 9 values (2,3,5,7) I found that 7 is a divisible of 77 ...so like the way you told that (Is it could be proved that 77 is a Prime no.)
Please reply as soon as I need your pleasure of thought weather my substitution is right or wrong?
77 is divisible by 7 ,so it's not prime.
No it is clearly not Prime. 7 is a prime number below 9 and divide 77 to produce a quotient of 11 and remainder is 0 .Sir's method is absolutely correct
thanks sir, it is going to help me in my next math quiz
Amazing class👏👏👏👏
Thankyou sir
Nice explanation
Tthank u sir
So cool 😎
How if you find larger number like 11,00021 ?
Using your method, 563. 5 + 6+ 3 = 14. 14 is divisible by 7 (prime). Therefore, 563 is not prime. But 563 IS prime.
No I think you got that wrong. It is only for divisibility by 3 that we test like that. For example to check whether 129 is divisible by 3 or not, we do 1+2+9=12. Since 12 is divisible by 3 so 129 is also divisible by 3.
This rule is only applicable in case of divisibility test by 3. For other numbers it is different.
For 563
Check the next perfect square i.e, 24²=576
So, all the prime nos. Below 24 are 2, 3, 5, 7, 11, 13, 17, 19, 23
Now check if 563 is divisible by any of them. You will find it is not divisible by any of them. So, 563 is prime number.
Check whether 26 is composite or not
Its not..as 2, 13 and 26 it self is it's factors
26 is not prime number
a good teacher
किती छान!
In case of 2?
Though it is obvious that 2 is a prime number?
For single digit like 2, 3,5, 7,