The cost of 2 cows is the same as the cost of 5 sheep. If the total

Question

The cost of 2 cows is the same as the cost of 5 sheep. If the total cost of 7 cows and 4 sheeps is $1,290, what is the cost of cows?

(A) $180 
(B) $170
(C) $160 
(D) $150
(E) $140

ravish844 · Answer

Hi  Bunuel ,

Option D and E are same and unfortunately, 150 is the correct answer. Could you please correct it?

Regards,
Ravish.

Posted from my mobile device

Bunuel · Answer

______________________
Fixed. Thank you.

LipiSinha · Answer

5 sheep = 2 cows
4 sheep =  \frac{8}{5}  cows

Cost of 7 +  \frac{8}{5}  cows = 1290

\frac{43}{5}  cows = 1290
1 cow = 150

Therefore, the answer will be D.

ScottTargetTestPrep · Answer

Solution:
 
We can let c = the cost of one cow and s = cost of one sheep. We can create the equations:

2c = 5s and 7c + 4s = 1290

Solving s in terms of c in the first equation, we have:

s = 2c/5

Substituting this into the second equation, we have:

7c + 4(2c/5) = 1290

35c/5 + 8c/5 = 1290

43c/5 = 1290

c = 1290 * 5/43 = 30 * 5 = 150

Answer: D

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