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: Option B

Solution(By Examveda Team)

Let initially X grass was present there,and it is increasing by Y grass per day, then for the first condition We get,
X+24*y = 24*70 ----(1)
For the 2nd condition, we have,
X+60*Y = 60*30----(2) Now, On solving equation (1) and (2), we get
X = 1600 and
Y = 10 /3
Third Condition,
X+96*Y = 96 *N -----(3) [N = Number of Cows required]
Putting the values of X and Y in equation (3), We get
N = 20.