Thursday, July 29, 2010

GMAT Question of the Day

A Cell divides into two each round hour. If at a certain round hour, two Cells were placed in a jar, how many Cells will be in the jar in N hours?

(a) 2N
(b) 22N
(c) 2N+1
(d) 2N-1
(e) 2N

Let’s find the number of Cells in the first hours.
After one hour (N=1) there will be 4 Cells.
After two hours (N=2) there will be 8 Cells.
After three hours (N=3) there will be 16 Cells.
Therefore the formula that fits this series is 2N+1.

The best answer is C.