LCM Easy method Find LCM of 18 and 24. Factors: 18:- 2x3x3 24:- 2x2x2x3 Now cancel out the commons: 18:- 3 24:- 2x2 Finally, cross multiply: 18 x (2x2) = 72 24 x (3) = 72 You don't even need to cross multiply both. Just go for one of them and that's the LCM. Different logic: If we wanna do this: (1/18) + (1/24) = (1/2x3x3) + (1/2x2x2x3) = (2x2/2x3x3x2x2) + (3/2x2x2x3x3) same denominator, = 2x2/72 + 3/72 Denominator is the LCM.
It's hard to explain this here using just text, but I'll see what I can do. For the first equation p + qr = odd, we have the following options: p -- e - o - o - o q -- o - e - o - e r -- o - o - e - e If p is odd in this equation, qr must be even. There are three possibilities for this, as listed above. Then, we can look at the second equation pq + qr = even. We could factor out a q to give q(p + r) = even. This gives us the options listed below. The first two options are what we get if q is odd, the remainder are if q is even. p -- e - o - e - e - o - o q -- o - o - e - e - e - e r -- e - o - e - o - e - o There are only two options that appear in both lists: p -- o - o q -- e - e r -- e - o In both of these cases, p must be odd. This is why (B) is the answer to this question. I hope that helps!
We did all we could to make these questions as close to the real thing as possible while still covering the content you'll need to know for the GRE. As Alex says from about 1:20, the questions in the video will start off easy, get progressively more difficult as the video progresses, and will end with a couple of questions that are equivalent to the kind of question you'll need to score 168+. I hope that helps!
LCM Easy method
Find LCM of 18 and 24.
Factors:
18:- 2x3x3
24:- 2x2x2x3
Now cancel out the commons:
18:- 3
24:- 2x2
Finally, cross multiply:
18 x (2x2) = 72
24 x (3) = 72
You don't even need to cross multiply both. Just go for one of them and that's the LCM.
Different logic:
If we wanna do this: (1/18) + (1/24)
= (1/2x3x3) + (1/2x2x2x3)
= (2x2/2x3x3x2x2) + (3/2x2x2x3x3)
same denominator,
= 2x2/72 + 3/72
Denominator is the LCM.
I can do all these question easily. What is the difficulty level ?
I've GRE exam tomorrow, it is helpful ❤
How did it go? Pls tell me!
For the last question, doesnt p have to be even, because if p is odd in the first equation (p+qr=odd), it will be odd + odd which = even.
It's hard to explain this here using just text, but I'll see what I can do. For the first equation p + qr = odd, we have the following options:
p -- e - o - o - o
q -- o - e - o - e
r -- o - o - e - e
If p is odd in this equation, qr must be even. There are three possibilities for this, as listed above.
Then, we can look at the second equation pq + qr = even. We could factor out a q to give q(p + r) = even. This gives us the options listed below. The first two options are what we get if q is odd, the remainder are if q is even.
p -- e - o - e - e - o - o
q -- o - o - e - e - e - e
r -- e - o - e - o - e - o
There are only two options that appear in both lists:
p -- o - o
q -- e - e
r -- e - o
In both of these cases, p must be odd. This is why (B) is the answer to this question.
I hope that helps!
Great video
Thank you!
Are these GRE questions difficulty level the same as the real GRE test?
We did all we could to make these questions as close to the real thing as possible while still covering the content you'll need to know for the GRE. As Alex says from about 1:20, the questions in the video will start off easy, get progressively more difficult as the video progresses, and will end with a couple of questions that are equivalent to the kind of question you'll need to score 168+.
I hope that helps!