As the weather gets cold, the grass on the pasture

Let 1 cow eat 1 serving of grass every day.

20 cows eat 100 for five days, 15 cows eat 90 for six days, 100-90= 10 (parts),

It showed that cold reduced 1 0 head of grass in1day, that is, cold was equivalent to 10 head of cattle grazing.

10 cattle represented by "grass on the grassland can feed 20 cows for 5 days" and "cold" are grazing at the same time.

Therefore, the pasture grass is (20+ 10) × 5 = 150 (parts).

pass by

150 ÷ 10 = 15 It is understood that the original grass in the pasture can feed 15 cows.

10 day, cold occupied 10 cattle,

Therefore, it can feed five cows 10 day.