Last Updated on May 11, 2023
GMAT OFFICIAL GUIDE DS
Solution:
We are given that a is a 3-digit integer and b is a 3-digit integer and need to determine whether the product of a and b is greater than 5.
Statement One Alone:
The units digit of a is 4.
Statement one alone is not sufficient to answer the question. For example, if the units digit of b is 1, then the units digit of the product of a and b is 4, which is less than 5; however, if the units digit of b is 2, then the units digit of the product of a and b is 8, which is greater than 5.
Statement Two Alone:
The units digit of b is 7.
Statement two alone is not sufficient to answer the question. For example, if the units digit of a is 1, then the units digit of the product of a and b is 7, which is greater than 5; however, if the units digit of a is 0, then the units digit of the product of a and b is 0, which is less than 5.
Statements One and Two Together:
Using the information from statements one and two, we see that since the product of the units digits of a and b is 4 x 7 = 28, the units digit of the product of a and b is 8, which is greater than 5.
Answer: C
