GMAT Problem Solving
The numbers x and y are three-digit positive integers, and x + y is a four-digit integer. The tens digit of x equals 7 and the tens digit of y equals 5. If x ＜ y, which of the following must be true?
I.The units digit of x + y is greater than the units digit of either x or y.
II.The tens digit of x + y equals 2.
III.The hundreds digit of y is at least 5.
- A II only
- B III only
- C I and II
- D I and III
- E II and III
Correct Answer: B