If 8 cows can eat 3 bales of hay in 9 days, how long will it take 3 cows to eat 18 bales of hay?

Answer 1

For the first case, there are 3 bales/9 days or (1/3) bales/day eaten

If there are 8 cows eating the same amount each day, then 1 cow eats (1/24) bales/day

Next, equate this to 18 bales: (1/24) bales/day = 18 bales/ x days or x = 432 days

But since there are 3 cows eating, you would decrease this by 1/3, so (1/3)(432) = 144 days