BTGModeratorVI wrote: ↑Tue Jul 07, 2020 6:18 am
A certain population of bacteria doubles every 10 minutes. If the number of bacteria in the population initially was 10^4, what was the number in the population 1 hour later?
(A) 2(10^4)
(B) 6(10^4)
(C) (2^6)(10^4)
(D) (10^6)(10^4)
(E) (10^4)^6
Answer:
C
Source: Official guide
Let's list some populations and
look for a pattern
Initial population: 10⁴
10 minutes later: (10⁴)(2)
20 minutes later: (10⁴)(2)(2)
30 minutes later: (10⁴)(2)(2)(2)
40 minutes later: (10⁴)(2)(2)(2)(2)
50 minutes later: (10⁴)(2)(2)(2)(2)(2)
60 minutes later: (10⁴)(2)(2)(2)(2)(2)(2) = (10⁴)(2⁶)
Answer: C
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
