If a farmer sells 20 of his chickens, his stock of feed will last for 3 more days than planned, but if he buys 15 more chickens, he will run out of feed 4 days earlier than planned. If no chickens are sold or bought, the farmer will be exactly on schedule. How many chickens does the farmer have? Choose the correct answer: A) 40 B) 60 C) 80 D) 90 E) 100
Let x = total feed required for the planned period   n= number of chicken   t = total time of the planned feed   x = nt   1) x = (n-15) * (t+4)   2) x = (n+20) * (t-3)   equating 1&amp;2   (n-15) * (t+4) = (n+20) * (t-3)   7n = 35t   n =5t   x= n * n/5   substituting this value in 1   n * n/5 = (n-15) * (n/5+4)   5n = 300   n =60   60
<result>B</result>
If a farmer sells 20 of his chickens, his stock of feed will last for 3 more days than planned, but if he buys 15 more chickens, he will run out of feed 4 days earlier than planned. If no chickens are sold or bought, the farmer will be exactly on schedule. How many chickens does the farmer have?