Download Aptitude Crack
img not found img not found

Series Completion - Verbal and Reasoning

Directions to SolveChoose the correct alternative that will continue the same pattern and replace the question mark in the given series.
Q1:

Which term of the series 5, 10, 20, 40, ..... is 1280?

A 10th

B 9th

C 8th

D None of these

ANS:B - 9th

Clearly, 5 x 2 = 10, 10 x 2 = 20, 20 x 2 = 40,.....So, the series is a G.P. in which a = 5 and r = 2.Let 1280 be the rath term of the series.Then, 5x2n-1 = 1280 2n-1 = 256 = 28 n - 1 = 8 n = 9.