Question

What is the common ratio for 100 -80 64 -51.2?

Answer 1

Common ratio is `-4/5`.

Explanation:

Common ratio is given by a term divided by its immediately preceding term and in a geometric progression this is always same and hence called common ratio.

`r = T_n/T_(n-1)= T_3/T_2 = T_2/T_1`

Here `(-80)/100=64/(-80)=(-51.2)/64=-4/5`

Hence, common ratio is `-4/5`.