Q2. Grass grow uniformly.40 cows take 40 days to eat the grass.30 cows take 60 days to eat the grass.how many days 20 cows will take
to eat the grass. (ans:120 days)
b = amount of grass at in the field at the begining.
g = amount the grass grows per day
c = amount of grass 1 cow eats per day.
d = how many days 20 cows will take to eat the grass
write eqs from given info:
eq1: b + 40g = 40c
eq2: b + 60g = 30c
eq3: b + dg = 20c