A farmer had d animals, all of which the farmer bought for the same price. The farmer decided to sell the animals. 18 of the animals were sold at a profit of 10% each while the rest were sold at a loss of 20% each. Overall, the farmer made neither a profit nor a loss. Which of the following is equal to d?  Choose the correct choice:	A) 21	B) 24	C) 27	D) 32	E) 36
Let P be the price the farmer paid for each animal.   The total profit on the 18 animals is 18*0.1*P.   The total loss on the other (d-18) animals is (d-18)*0.2*P.   (d-18)*0.2*P = 18*0.1*P   0.2*d = 1.8 + 3.6   d = 27   The answer is 27.
<result>C</result>
A farmer had d animals, all of which the farmer bought for the same price. The farmer decided to sell the animals. 18 of the animals were sold at a profit of 10% each while the rest were sold at a loss of 20% each. Overall, the farmer made neither a profit nor a loss. Which of the following is equal to d?