I'll take the first one. 1) A seminar consisted of morning session and afternoon session. If each of the 128 people attending attended at least one of the two sessions, how many of the people attended the morning session only? a. ¾ attended both sessions b. 7/8 attended the afternoon session Set up...

I'm having a little trouble understanding what you're doing here. But I can tell you that the easiest way to understand this is to apply a 45/45/90 right triangle. The diagonal of a square is always equal to (side)(sqrt 2). For example, if each side of a square is 5, then the diagonal is 5sqrt2. Or ...

I have figured out what you're doing wrong, Night Reader, and just in case anyone else is wondering I'll explain. Our job is to figure out how many 10s we can make from the list of factors, but it has to be AT THE SAME TIME. We aren't making new combinations of 2s and 5s to make new 10s. It's how ma...

But it's all irrelevant. You can't use a calculator to work out 40! on test day. You can't use excel or an online calculator or anything. And you don't have time to do it by hand. The value of 40! is irrelevant. What matters is your solving methodology, and it is COMPLETELY NOT FEASIBLE to do this a...

P isn't the number that you're dividing by. P is the power of ten that's the largest you can divide 10! by.

Manhattan GMAT generally uses a red color scheme and tends to be very good quality. People are probably talking about Manhattan GMAT, though sometimes, confusingly, they'll use the word "review" too because... well, you're reviewing for a test, right? Manhattan Review is an unrelated comp...

There's a much faster way to do that one, Brian.

Rewrite 36 as a product of its prime factors.

(2^2)(3^2)

Take each of the exponets, and add one to each.
(2+1)(2+1)
Multiply those
(3)(3) = 9

36 had 9 factors.

That works all the time.

It really only goes to 51 on the real test, as far as I know. I got a 50Q/50V a few months ago and that was a 780.