If a, b and c are in A.P. and also in G.P., show that : a = b = c.

The sum of first four terms of the G.P. 2, 6, 18, ………, is :

1. 26

2. 80

3. 160

4. 52

The geometric mean between 8 and 32 is :

1. 24

2. 256

3. 40

4. 16