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A certain zoo has 288 mammals, 25 percent of which are

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by swerve » Thu Aug 09, 2018 10:41 am

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Source: Veritas Prep

A certain zoo has 288 mammals, 25 percent of which are female. What percent of the mammals in the zoo were born at the zoo?

(1) The number of male mammals that were born at the zoo is three times the number of female mammals who were not born at the zoo.
(2) The number of male mammals that were not born at the zoo is three times the number of male mammals that were born at the zoo.

OA C.
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Source: — Data Sufficiency |

error

by deloitte247 » Sat Aug 18, 2018 10:57 am
..
Last edited by deloitte247 on Sat Aug 18, 2018 11:57 am, edited 1 time in total.
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by deloitte247 » Sat Aug 18, 2018 11:25 am
Male (born at zoo) + Male (not born at zoo)
= 75% of 288 = 216
Female (born at zoo) + Female (not born at zoo)
= 25% of 288 = 72
Question : What % of the mammal were born at zoo?
Statement 1 : The number of male mammals that were born at zoo is 3 times the number of female mammals that were not born at zoo.
Therefore, Male (born at zoo) = 3x female (not born at zoo)
The information here is not enough to determine the % of mammals born at zoo.
Hence, statement 1 is NOT SUFFICIENT.

Statement 2 : The number of male mammals that weren't born at zoo is 3 times the number of male mammals that were born at zoo.
This means it's in ratio 3 : 1
$$Male\left(born\ at\ zoo\right)\ =\ \frac{216}{3\ +\ 1}\ =\ \frac{216}{4}\ =\ 54$$
but there i no information about the female, hence, statement 2 is INSUFFICIENT.
Statement 1 and 2 together
Male (born at zoo) = 3 * female (not born in zoo)
Male (born at zoo) = 54
$$\frac{54}{3}=\ \frac{\left(3\ \cdot\ female\ \left(not\ born\ at\ zoo\right)\right)}{3}$$
Female (not born at zoo) = Total no. of females (not born in zoo)
= 72 - 18 = 54
Mammals (born at zoo) = Male (born at zoo) + Female(born at zoo)
Mammals (born at zoo) = 54 + 54 = 108.
$$\%\ of\ mammals\ born\ at\ zoo\ =\ \frac{108}{288}\cdot\ \frac{100}{1}$$
= 37.5%
Statement 1 and 2 combined together is SUFFICIENT.
Option C is CORRECT.
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