sonaketu wrote:

The number of undergraduate degrees in engineering awarded by colleges and universities in the United States increased by more than twice from 1978 to 1985.

(A) increased by more than twice

(B) increased more than two times

(C) more than doubled

(D) was more than doubled

(E) had more than doubled

Can soneone please explain when to use double,twice, two times. I always seem to get confused.

"To double" is a verb.

Double might also be used as an adjective.

"Twice" is used when an adverb is called for.

Correct usage:

The number doubled. OR, The number more than doubled.
That is why (C) is the correct choice: it employs "to double" as a verb in the appropriate, simple past tense. (this sentence does not call for past perfect or for passive voice as in E and D).

Also correct: double beds. A double shot of espresso. (adjectives).

"Twice" is an adverb, modifying some action. BUT....

If you say that something "increased twice" or "increase two times", that does

not imply a 100% increase in quantity. That says that the quantity increased in steps: once (by some unstated amount), and then a second time (by some unstated amount). That obviously has an entirely different meaning that "to double."

Twice is pretty much exactly interchangeable with

two times as far as I can think of at the moment. Some correct usages:

I took the GMAT twice (adverb).

Last week the stock increased twice: on Tuesday and on Thursday. But it was down on Monday, Wednesday, and Friday.

I played in twice as many games as Bob did.