China Naming Network - Fortune telling knowledge - 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 ④From ①④, we get (40-2·X)·V=V' ⑤
From ③⑤, we get X =10