There are just two ways in which 5 may be expressed as the sum of two different positive (non-zero) integers, namely 5 = 4 + 1 = 3 + 2. In how many ways, 9 can be expressed as the sum of two different positive (non-zero) integers?

P and Q are two positive integers such that PQ = 64. Which of the following cannot be the value of P + Q?

If n is an integer between 20 and 80, then any of the following could be n+7 except

If x, y, z be the digits of a number beginning from the left, the number is

How many numbers between  1000 and 5000 are exactly divisible by 225 ?

If m and n are positive integers and (m – n) is an even number, then (m2 – n2) will be always divisible by

When a number is divided by 56, the remainder obtained is 29. What will be the remainder when the number is divided by 8 ?

(49)^15 – 1 is exactly divisible by :

If a and b are two odd positive integers, by which of the following integers is (a^4 – b^4) always divisible ?

A number when divided by 91 gives a remainder 17. When the same number is divided by 13, the remainder will be ?