Maisie decides to stock rabbits at her pet store, unaware that rabbit

Question

Maisie decides to stock rabbits at her pet store, unaware that rabbit populations double every eight months. If she starts with 6 rabbits, how many rabbits will she have in 4 years, if none of them are sold or die during this period?

A. 96
B. 192
C. 256
D. 324
E. 384

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tgsankar10 · Answer

Population doubles every 8 months.

P(1+100	ext{%})^{(\frac{	ext{n months}}{8})}

P*2^{(\frac{	ext{n months}}{8})}

In 4 years, there are 48 months

P*2^{(\frac{48}{8})}=P*2^6=6*2^6=6*64=384

Answer: E

julemirza · Answer

I am confused I tried to use the sum of a geometric sequence formula for this Sn = (a(r^n -1))/ r- 1 
However the result then gives me 378 when n is 6

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TheVDR · Answer

We need the "n"th term and not sum of terms, as we have been asked the number after 4 years.

If we sum them with n=6, we basically get a 6 * (2^5 + 2^4...+ 2^1 + 1) = 378, but all we want is the 6th term of the series while considering the 0th term is 6. That would be 6 * 2^6 = 384, which is obviously 6 more than the series above.

tgsankar10 · Answer

When you use geometric series for this, n should be 7.

First term is 6 and then there are 6 more terms. So total 7 terms in the G.Series.

Also, we need  n^{th}  term not Sum of terms.

Rod728 · Answer

Maisie decides to stock rabbits at her pet store, unaware that rabbit populations double every eight months. If she starts with 6 rabbits, how many rabbits will she have in 4 years, if none of them are sold or die during this period?

A. 96
B. 192
C. 256
D. 324
E. 384

1) Our final value will be  6*2^x  , where x is equivalent to the 8-month periods which the population doubles.
2) 4 years = 4* 12 months = 48 months. ->>  48 months/ 8 months = 6  periods.
3) Finally, 6*2^6= 6*64=  384  ->>  Answer E

DhanyaAbhirami · Answer

> 1 rabbit Became $2=2^1$ times in $8$ months
> 1 rabbit Became $2^{6}$ times in $8	imes6=48$ months
> 6 rabbit Became $2^{6}	imes6=384$ in $48$ months

Maisie decides to stock rabbits at her pet store, unaware that rabbit

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Maisie decides to stock rabbits at her pet store, unaware that rabbit

Prep Toolkit

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