The 8 term of a go is 640 if the first term is 5 find the common ratio and the 10 term

Answer 1

8th term is 640 ----> ar^7 = 640
but a = 5
5r^7 = 640
r^7 = 128
r = 2

then term(10) = ar^9 = 5(2^9) = 5(512) = 2560

Answer 2

Tn = 5 r^(n-1)
T8 = 5 r^7 =640
r^7 = 128
r = 2
T10 = 5 * 2^9= 5 * 512 = 2560