Which one of the following is the minimum value of the sum of two integers whose product is 36?

37

20

15

12

Correct Answer : D

What is the unit's digit of the number 6^{256}–4^{256}

N is the smallest number that has 5 factors. How many factors does (N - 1) have??

If x is a number satisfying 2 < x < 3 and y is such that 7 < y < 8, which of the following expressions will have the largest value?