These sample questions have been taken from the old GMAT question papers.
Answer each question yourself before reading the analysis that follows each question.
A group of associates needed to invest $80,000 each in order to purchase a certain resort. After an additional associate joined the group, the amount that each associate, including the new one, needed to invest was $ 60,000. How much money did the group need to invest in order to purchase the resort?
If the number of associates was N, then it follows that 80,000N = 60,000(N+1).
80,000N = 60,000N + 60,000
The amount needed to buy the resort was therefore 3*80,000=240,000
So, (D) is the answer.
GMAT : Model Questions Index