If the product of `n` positive numbers is `n^n`. Then their sum is

The product of n positive numbers is 1, then their sum is a positive integer, that is

If the sum of first n positive integers is 1/5 times the sum of their square then n equals

If the sum of first n terms of an A P is c n^2, then the sum of squares of these n terms is (2009)

Prove that the sum of first n positive odd numbers is n^(2)

Let a_n=16 ,4,1, be a geometric sequence. Define P_n as the product of the first n terms. Then the value of 1/4sum_(n=1)^oo P_n^(1/n) is _________.

The sum of the squares of the first n natural numbers is 285, while the sum of their cubes is 2025. Find the values of n.

If a_1,a_2, .....,a_n are positive real numbers whose product is a fixed number c , then the minimum value of a_1+a_2+.........+a_(n-1)+2a_n is a. a_(n-1)+2a_n b. (n+1)c^(1//n) c. 2n c^(1//n) d. (n)(2c)^(1//n)