The Answer to the Question
is below this banner.
Here's the Solution to this Question
There are three types of animals and 10 stalls. One stall can be filled by any of three animals. Once the first stall is filled, the second stall can be filled again in three ways by placing any of three animals in it. We have to fill 10 such stalls and number of each animal is at lest 10, so we have
to fill 10 stalls.