Traditional Culture Encyclopedia - Weather inquiry - As the weather gradually gets colder, the grass on the pasture not only does not grow, but is reduced at a fixed rate.

If the grass on a certain meadow can be eaten by 40 cows10

As the weather gradually gets colder, the grass on the pasture not only does not grow, but is reduced at a fixed rate.

If the grass on a certain meadow can be eaten by 40 cows10

Suppose there is S grass, a cow eats grass at a rate V, the grass decreases at a rate V', and X cows eat it for 20 days, then

S=(40·V+V') ·10 ①

S=(30·V+V')·12 ②

From ①②, the ratio of the two speeds is V'/V=20 /1 ③

< p>And S=(X·V+V')·20 ④

From ①④, we get (40-2·X)·V=V' ⑤

From ③⑤, we get X =10