# Math Help - Geometric Progressions question help

1. ## Geometric Progressions question help

A machine is required to have 5 speeds, lowest being 60 rev/min and the highest being 680 rev/min. state the complete range of speeds i) in AP and ii) in GP

i have done the AP part, i am a little stuck with where to start with the GP part as i have the 1st and 5th terms of the sequence

a starting pointer would be helpful if anyone could give me a pointer thanx

2. If this is a geometric progression, then it is $a=60$, $a\cdot q$, $a\cdot q^2$, $a\cdot q^3$, $a\cdot q^4=680$ for some $q$. From here, you can find $q$.