The number of bacteria in a petri dish increased by 50 percent every 2 hours. If there were 108 million bacteria in the dish at 2: 00 p.m., at what time will there be 243 million bacteria in the dish? Choose the correct choice from the following answers:
A) 6: 00 p.m.
B) 8: 00 p.m.
C) 6: 00 a.m.
D) 8: 00 a.m.
E) 10: 00 a.m.
Given:   he number of bacteria in a petri dish increased by 50 percent every 2 hours   There were 108 million bacteria in the dish at 2: 00 p.m   Since the bacteria is increasing by 50% every 2 hours, this means that the number is multiplied by 1.5 every 2 hours.   Required: At what time will there be 243 million bacteria in the dish?   Assume that there are n intervals of 2 hours between 108 million and 243 million.   108 * (1.5)^n = 243   (3/2)^n = 243/108 = 9/4= (3/2)^2   Hence n = 2 intervals.   Each interval is of 2 hours. Therefore, the number of hours = 4   Adding 4 hours to 2 PM, we get 6 PM as the answer.   Option 6: 00 p.m.
<result>A</result>
The number of bacteria in a petri dish increased by 50 percent every 2 hours. If there were 108 million bacteria in the dish at 2: 00 p.m., at what time will there be 243 million bacteria in the dish?