SOLUTION: If a sheep and cow and eat a pile of grass in 30 days and the same sheep and goat can eat the same pile of grass in 45 days and the same cow and goat can eat the same pile of gra

Question 796982: If a sheep and cow and eat a pile of grass in 30 days
and the same sheep and goat can eat the same pile of grass in 45 days
and the same cow and goat can eat the same pile of grass in 60 days
So how many days will it take the sheep, cow and goat to finnish same pile of grass??
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Express their rates of eating as:
( 1 pile of grass ) / ( time to eat the pile in days )
-----------------------------------
Let = sheep's rate of eating grass
Let = cow's rate of eating grass
Let = goat's rate of eating grass
-----------------------------------
(1)
(2)
(3)
----------------------
Subtract (3) from (2)
(2)
(3)

Add this equation to (1)
(1)

---------------------

and
(1)
(1)
(1)
(1)
and
(3)
(3)
(3)
------------------

The sheep, cow and goat will take 2.71 days to finish the pile of grass
You can check the math- my method should be OK

RELATED QUESTIONS
A goat and a sheep can eat all the grass on a field in 90 days. A sheep and a cow can eat (answered by ankor@dixie-net.com)

If 15 oxen or 20 cows can eat the grass of a field in 80 days, then in how many days will (answered by josmiceli)

Please help me with this question. A piece of pasture grows at a constant rate every... (answered by stanbon,miampetite)

A Goat can eat all the grass in a farmer's field, in 12 days, whereas a cow can finish it (answered by flame8855)

5 sheep ate 150kg of grass in 15 days how many days will 9 sheep eat 90kg of... (answered by Theo,greenestamps,ikleyn)

One ox eats the same amount as 15 sheep. Two people rent a field for $175. Person A... (answered by mananth)

A lion can eat a sheep in 2 hours, a wolf can eat a sheep in 3 hours, and a dog can eat... (answered by jim_thompson5910,ikleyn,greenestamps)

A lion eats one sheep in 4 hours, a leopard eats one sheep in 5 hours, and a bear eats... (answered by Alan3354)

The hundred-handed monster Briareus was hungry and attacked a flock of 98 sheep. He... (answered by Solver92311)