Olympiad math problem! ~ hate hate hate hate hate hate hate hate hate hate.

Cattle eat grass: 45 * 6 = 270 = * * 270 portions of grass 36 * 9 = 324 324-270 = 54 54/(9-6) =18 = snow speed 270-18 * 6 =1.

We still need to keep 18 people (these should be right, I think).

Solution: Suppose X water is evaporated every day, and Y water is needed per hectare.

520 * y * 50+50x = 1324 * 20 * y+20x

x= 16y

There is water in the reservoir: 26800y

Water evaporates within 40 days: 40x=640y.

The water that can supply the land for 40 days is 26800y-640y = 26 160y.

So it can supply 26 160 ÷ 40 = 654 hectares of land water.