10th term in 16,8,4

this is gp because

because ratio of next term to previous term is always same.

8/16 = 4/8 = 1/2

so common ratio is 1/2

first term is a = 16

so nth term of a gp is given as

Tn = ar^ (n-1)

T10 = 16 * (1/2) ^ (10-1)

= 16 * (1/2) ^9 = 1/32