If the sum of first four terms of GP is 30, sum of last four terms of GP is 960 and first term is 2 then find common ratio.

Answer 1

2(r^4-1)/(r-1) = 30
r=2

The last 4 terms don't matter, unless you are interested in how many there are.

Answer 2

2(r^4-1)/(r-1) = 30
r=2
Cannot we say by comparing? there is no simplification? How can u say that direct answer is ?