if 10 machines can produce 20 units in 10 hours , how long would it take 40 machines to produce 100 units ?
"10 machines would produce 100 units in 50 hours . increasing the amount of machines by 4 would mean dividing 50 hours by 4 . 50 / 4 = 12.5 answer : e"
divide(100, multiply(divide(divide(20, 10), 10), 20))