For how many positive integers n is it true that the sum of 13/n, 18/n and 29/n is an integer?

For how many positive integers ‘n’, n^3-8n^2+20n-13 is a prime?

How many two-digit positive integers N have the property that the sum of N and the number obtained reversing the order of the digits of N is a perfect square?

For any positive integer n prove that n^(3)-n is divisible by 6

For how many integers n between 5 and 20, inclusive, is the sum of 3n, 9n and 11n greater than 200?

For which positive integers n is the ratio, (sum+(k=1)^(n) k^(2))/(sum_(k=1)^(n) k) an integer ?

For any positive integer n, prove that n^(3) - n is divisible by 6.

For any positive integer n,prove that n^(3)-n is divisible by 6

For which positive integers n is the ratio (sum_(k=1)^(n)k^(2))/(sum_(k=1)^(n)k) an integer?

For any positive integer n, prove that (n^(3) - n) is divisible by 6.