Last Updated on May 10, 2023
GMAT OFFICIAL GUIDE DS
Solution:
We are given that the balance in a checking account increased from May 1 to May 30. We must determine the balance of the account on May 30.
Statement One Alone:
If, during this period of time, the increase in the balance in the checking account had been 12 percent, then the balance in the account on May 30 would have been $504.
Using the information in statement one we can create the following equation in which x = the balance of the account on May 1:
1.12x = 504
x = 450
Although we see that we can determine the balance of the account on May 1, we still cannot determine the balance on May 30 (since we don’t know the actual percent increase). Statement one is not sufficient to answer the question. We can eliminate answer choices A and D.
Statement Two Alone:
During this period of time, the increase in the balance in the checking account was 8 percent.
Using the information in statement two we do not have enough information to determine the balance of the checking account on May 30 (since we don’t know the balance of the account on May 1). We can eliminate answer choice B.
Statements One and Two Together:
Using the information from statement one, we determined the balance on May 1 to be $450. Statement two tells us that the balance increased 8 percent from May 1 to May 30. Thus, we can determine the account balance on May 30. While it’s not necessary to calculate the actual balance, the work is shown below.
1.08(450) = 486
The checking account balance on May 30 was $486. This is sufficient to answer the question.
Answer: C
