if 5 machines can produce 20 units in 10 hours , how long would it take 10 to produce 80 units ?
"5 machines would produce 80 units in 40 hours . increasing the amount of machines by 2 would mean dividing 40 hours by 2 . 40 / 2 = 20 answer : b"
divide(80, multiply(divide(divide(20, 10), 5), 20))