Question

If 29 sheep can feed on a field of uniformly growing grass in 7 days or 25 sheep can feed on the same field in 9 days, then how many sheep will feed the field in 6 days?

Answer 1

Answer:

Let each sheep can eat 'x' quantity of grass and growth rate is 'y' per day, then

Total grass eaten by 29 sheep in 7 days = grass eaten by 25 sheep in 9 days

=> 29x + 7y = 25x + 9y

=> 4x=2y or y=2x

Thus total quantity of grass=29x + 7(2x) or 25x + 9(2x) = 43x

Let 'a' number of sheep are required to feed the same grass in 6 days, then 43x = ax + 6y

=> 43x = ax + 6(2x)

=> a=31