if 5 machines can produce 20 units in 10 hours , how long would it take 10 to produce 60 units ?
"5 machines would produce 60 units in 30 hours . increasing the amount of machines by 2 would mean dividing 30 hours by 2 . 30 / 2 = 15 answer : c"
divide(60, multiply(divide(divide(10, 10), 5), 20))