Population Growth Problem FLASHCARDS

[rockrock]

Is the statement sufficient?

A group of rabbits multipllies at a constant rate. By what factor does its population increase every day?

(1) The population grows from 200 to 5,000 in one week.

I know we aren't supposed to calculate the answer, but I have a question about how it IS calculated.

The solution: In 7 days the population increases by a factor of 5000/200 = 25. In one day it increases by a factor of 7th root of 25.

Why do we take the 7th root?

[gpinder77]

Is the statement sufficient?

A group of rabbits multipllies at a constant rate. By what factor does its population increase every day?

(1) The population grows from 200 to 5,000 in one week.

I know we aren't supposed to calculate the answer, but I have a question about how it IS calculated.

The solution: In 7 days the population increases by a factor of 5000/200 = 25. In one day it increases by a factor of 7th root of 25.

Why do we take the 7th root?

hmm.....not sure why are calculating the nth roots but.....i would would it like this.

5000-200 = week growth/7 = daily growth.

so the statement is sufficient to answer the question

[tim]

um, no. when the population grows or multiplies at a constant rate, you divide the final by the initial then take the nth root, as the original poster said. but yes you would never actually calculate the 7th root of 25 on the GMAT; just knowing it could be done makes the information sufficient..