Find the common ratio of the sequence 2,8,32,128 ...

4 because that is what's multiplied throughout

The common ratio is the common multiple of consecutive terms, usually denoted as "r" for the common ratio. Mathematically the common ratio is a constant that one finds when any term is divided by the term preceding it, in this case:

r=128/32=32/8=8/2=4

So the common ratio is 4.