Farmer has 7 choice for cow out of which he choose only 2
4 choice for pig and he choose only 3 pigs
10 choice for sheep and he choose all 10 sheep
Number of ways of choosing cows = 7C2
Number of ways of choosing pigs = 4C3
number of ways of choosing sheep = 10C 10
all these three groups of different animals can make different groups when taken together
That is : 7C2 * 4C3 * 10C10 = 21 * 4 * 1 = 84 ways
Answer : 84