Question

Grass in lawn grows equally thick and in a uniform rate. It takes 24 days for 70 cows and 60 days for 30 cows to eat the whole of the grass. How many cows are needed to eat the grass in 96 days?
A.22 Cows
B.20 Cows
C.18 Cows
D.16 Cows

Answer 1

Hello,

Let initially 'c' grass was present there.

It is increasing by 'y' grass per day.

Then,

For the first condition we get,

c+24*y = 24*70 - - - - - (1)

For the 2nd condition, we have,

c+60*y = 60*30 - - - - - (2)

Now,

On solving equation (1) and (2), we get,

c = 1600

And,

y = 10 /3

Third Condition,

c+96*y = 96 *N - - - - - (3) [N = Number of Cows required]

Putting the values of c and y in equation (3), we get
N = 20

Correct option B) 20 cows

Thank you!

Answer 2

B. 20 cows

Hi friend this is ur answer

Hope it helps u