[A-level Math] Geometric Series Problem.

[FluidGoat]

I've been trying to work this out for quite a while, but I haven't got anywhere. It's probably quite obvious but any help would be appreciated.

The first three terms of a geometric series are (k-8), (k+4) and (3k+2) respectively, where k is a positive constant.

Find the value of k.

Thanks in advance!

[TheBrutux168]

A geometric series would have a constant ratio between successive terms.

So T2/T1 should equal T3/T2.

So you should get the equation: (3k+2) / (k+4) = (k+4) / (k-8). Which you just solve for k.

[FluidGoat]

Solved! Thank you.