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In a growth period, a population of flies triples every week. If the original population had 3 flies, how big is the population after 4 weeks?
A. 2187
B. 729
C. 243
D. 27
E. 81
Correct Answer: C
Explanation/Reference:
Explanation:
We know that the initial population is 3, and that every week the population will triple.
The equation to model this growth will be i(r)n, where i is the initial size, r is the rate of growth, and n is the time.
In this case, the equation will be 3(3)4.
3(3)4 = 3(81) = 243 Alternatively, you can evaluate for each consecutive week.
Week 1: 3(3) = 9 Week 2: 3(9) = 27 Week 3: 3(27) = 81Week 4: 3(81) = 243
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