Question

Find the missing term in the geometric sequence : 8 , 20 , 50, 125 , ____

Answer 1

312.50

Explanation:

8 , 20 , 50, 125 , 312.50

First term, a = 8

Second term, ar = 20

Find common ratio, r

Substitute a = 8 into second equation

ar = 20

8r = 20

r = 20/8

r = 2.5

Find the fifth term

ar⁴

= 8 * 2.5⁴

= 8 * 39.0625

= 312.50

Fifth term, ar⁴ = 312.50