Oops... I could understand everything now. Can't understand how I couldn't figure this out before, haha. Thanks a lot anyway!

I would go with (A). This answer choice is definitely not a necessary assumption, as the air-pollution regulations could have caused a 30% decrease in air-pollution and this would cause a lot of changes already.

Rishab, you are definitely right. I answered it in 1:10, timing it with the timer at the top. Anyway, this doesn't mean much, I just wanted to have an idea on how much I need to improve in combinatorics. I still have a long way on inequalities, word problems, etc. But at least I can get a good numbe...

Thanks a lot!! "like" is used to compare nouns. "as" is used to compare actions. Here we are comparing how the nerve is stimulated by spicy food and how the nerve is stimulated by a raise in temperature. Since we are comparing two actions, we use "as" and not "like...

How can I improve my skills on Algebra?

Hello. I have just started to study for GMAT last week, and I intend to do the test by march. Since I'm not a native english speaker, I still have a long way to go on Verbal, but I decided to start with math. After studying geometry for 3 or 4 days (I used the Manhattan GMAT book), I could learn a l...