SAT Math Multiple Choice Practice Question 33: Answer and Explanation
11. The number n satisfies the following properties:
I.It has three digits.
II.Its units digit is the sum of its tens digit and its hundreds digit.
III.It is a perfect square.
Which number could be n?
Correct Answer: E
E. All the numbers have three digits. Only Choices (A), (D), and (E) have a units (ones) digit that equals the sum of the other two digits. And, using a calculator, you can see that the square roots of 156 and 516 are decimals, while the square root of 729 is 27, which makes it your answer.