Sum of n terms of the following series 13 + 33 + 53 + 73 + ... is
n2(2n2 - 1)
n3(n - 1)
n3 + 8n + 4
2n4 + 3n2
GM and HM of two numbers are 10 and 8 respectively. The numbers are
5, 20
4, 25
2, 50
1,100
A.
5, 20
Given, GM = 10 and HM = 8
On solving Eqs. (i) and (ii) a = 5, b = 20
If three positive real numbers a, b, c are in AP and abc = 4, then the minimum possible value of b is 2
If a, b, c are in GP (a> 1, b > 1, c > 1), then for any real number x (with x > 0, x 1), are in
GP
AP
HP
GP but not in HP