What will come in place of the x in the following Number series?

What will come in place of the x in the following Number series? 15, 60, X, 960, 3840

Quiz

Answer/Solution

960

Steps/Work

(B)
15 x 4 = 60, 60 x 4 = 240, 240 x 4 = 960, 960 x 4 = 3840.