if 8 workers can build 8 cars in 8 days , then how many days would it take 7 workers to build 7 cars ?
"8 workers can build 1 car per day on average . 1 worker can build 1 / 8 of a car per day . 7 workers can build 7 / 8 car per day . the time required to build 7 cars is 7 / ( 7 / 8 ) = 8 days the answer is c ."
multiply(divide(multiply(8, 8), 8), divide(7, 7))