Nine identical sparrows peck at less than 1001 grains, while ten such sparrows peck at more than 1100 grains. How many grains does each sparrow peck?

#
A sparrow can peck only an integer number of seeds.

## Solution

Since 10 sparrows peck more than 1100 seeds, 9 sparrows will peck more than (1100 : 10) $\cdot$ 9 = 990 seeds. At the same time, it is known that 9 sparrows peck fewer than 1001 seeds.

The only number divisible by 9 in the range from 991 to 1000 is 999. Therefore, 9 sparrows peck 999 seeds, and one pecks 111 seeds.

## Answer

111 seeds.