For any three positive real numbers a, b and c,
Question:

For any three positive real numbers $a, b$ and $c, 9\left(25 a^{2}+b^{2}\right)+25\left(c^{2}-3 a c\right)=15 b(3 a+c)$. Then :

1. a, b and c are in G.P.

2. b, c and a are in G.P.

3.  b, c and a are in A.P.

4. a, b and c are in A.P.

Correct Option: , 3

Solution: