A group of 10 is going to be selected from a pool of 8 men and 8 women...

In how many ways ways can the selection be carried out if:

a) we choose 10 people at random?

b) there must be 5 men and 5 women?

c) there must be more women than men?

Also, if you have time, can you answer:

- How many strings of 6 decimaal digit.s have exactly three digits that are 4's?

I suck at this problems and help would be great! Thank you!