Q.
A committee of 3 persons is to be constituted from a group of 2 men and 3 women. In how many ways can this be done? How many of these committees would consist of 1 man and 2 women?
There will be as many committees as there are combinations of 5 different persons taken 3 at a time. Hence, the required number of ways =5C3=3!2!5! =24×5=10.
Now, 1 man can be selected from 2 men in 2C1 ways and 2 women can be selected from 3 women in 3C2 ways. Therefore, the required number of committees =2C1×3C2 =1!1!2!×2!1!3!=6