A clock goes fast by one minute during the first hour, by two minutes at the end of the second hour, by 4 minutes at the end of 3rd hours, by eight minutes by the end of 4th hour, and so on. At the end of the which hour, will it be fast by just over sixty minutes?

Options

A. Fifth
B. Sixth
C. Seventh
D. Eighth

Answer

C

Explanation

First hour `rarr` 1 minute
second hour `rarr` 2 minutes, Third hour `rarr` 4 minutes
Fourth hour `rarr` 8 minutes
Fifth hour `rarr` 16 minutes
Sixth hour `rarr` 32 minutes