There are 160 horses and 340 sheep on a certain farm. If 20% of the ho

Question

There are 160 horses and 340 sheep on a certain farm. If 20% of the horses and 35% of the sheep are eight years old or older, what percent of the horses and sheep on the farm are under the age of eight?

A. 15.6%
B. 30.2%
C. 55%
D. 56%
E. 69.8%

Kudos for a correct solution.

A. 15.6%
B. 30.2%
C. 55%
D. 56%
E. 69.8%

Kudos for a correct  solution .

Cadaver · Answer

Coming out to be 69.8 % E

gmat6nplus1 · Answer

32 horses are eight years or older, thus 128 are younger. 
119 sheeps are eight years or older, thus 221 are younger.

Total sheeps and horses younger than eight: 349
Total sheeps and horses 500.

349/500 is very close to 350/500 which is 70%. Considering the error chose E.

Answer E.

arunrnair · Answer

Ans : E

Done calculation. Any short cut logic to do this.

nothintosayuc · Answer

We know that the percentage of animals on the farm age 8+ must be between 20 and 35%. Thus the percentage of animals younger than 8 must be greater than 35%. Only one that works in this instance is 69.8%.

PareshGmat · Answer

Answer = E. 69.8%

Required percentage  = \frac{500 - (\frac{20}{100}*160 + \frac{35}{100}*340)}{500} * 100 = \frac{349}{500}* 100 = 69.8%

EMPOWERgmatRichC · Answer

Hi All,

This question has a great Weighted Average "shortcut" built into it, but the only way to find it is to pay attention to the answer choices.

We're told that 20% of the horses and 35% of the sheep are age 8 or older. We're asked what percent of the total animals are UNDER the age of 8.

From a percent standpoint, we know that 80% of the horses and 65% of the sheep MUST be under the age of 8. Depending on whether we have more horses or more sheep, the "average" will gravitate either closer to 80% or closer to 65%, but it WILL be in that range (because that's how averages "work"). Looking at the answers, there's only one that's in that range....

Final Answer:  E

GMAT assassins aren't born, they're made,
Rich

dharam831 · Answer

There are 160 horses and 340 sheep on a certain farm. If 20% of the horses and 35% of the sheep are eight years old or older, what percent of the horses and sheep on the farm are under the age of eight?

A. 15.6%
B. 30.2%
C. 55%
D. 56%
E. 69.8%

Kudos for a correct solution.

A. 15.6%
B. 30.2%
C. 55%
D. 56%
E. 69.8%

Total Horse+Sheep = 500
Horse+Sheep under 8 years = (0.8)*160+(.65)*340 = 128+221 = 349
% = 349/5 = 69.8

Bunuel · Answer

VERITAS PREP OFFICIAL SOLUTION

Correct Answer: (E)

Start with an equation: .2(160) + .35(340) are over eight. To compute these mentally, start with 10% of each number. 10% of the horses = 16, so 20% = 2 * 10% = 32. 10% of the sheep = 34, so 35% of the sheep = 3.5 * 10% = 119. The percentage of animals over eight = (32+119)/500 (the total), or 151/500. This means that the percentage of animals UNDER eight – the percentage the question is asking for – must be 349/500. Estimate: 349/500 = about 35/50 = about 70%, or answer (E).

rombo27 · Answer

The question can be solved in 30 seconds without any need of calculations.

20% of horses are equal or older than 8 years. Hence 80% of the horses are younger than 8 years. 
35% of sheep are equal or older than 8 years. Hence 65% of the horses are younger than 8 years.

The correct answer must be in the following range 65%< X < 80%

Only one given option satisfies this equation. Answer E.

CrackverbalGMAT · Answer

This is a pretty simple question if you do by weighted average.
Since 20% of the horses and 35% of the sheep are eight years old or older.
Then 80% of the horses and 65% of the sheep are under the age of eight.
So by the weighted average.
The percent of the horses and sheeps is between 65% and 80%.
So only answer choice match here is E.

There are 160 horses and 340 sheep on a certain farm. If 20% of the ho

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