a. How many even numbers less than 500 can be formed using the digits 1, 2, 3, 4 and 5?

Each digit may be used only one in any number.

b. A committee of 8 people is to be chosen from 7 men and 5 women.

Find the number of different committees that could be selected if

i. The committee contains at least 3 men and at least 3 women,

ii. The oldest man or the oldest women, but not both must be included in the committee.