Combination/ Permutation Question

I have a few questions i don't understand T_T

1. A committe of 4 people is to be chosen form a group of 8 people- 4 women and 4 men. How many ways can the committee be chosen so as to include exactly 3 women.

The answer is 70 but i keep getting 96. I don't understand how they got 70 =3=

2. From a deck of 52 cards, the 12 face cards and 4 aces are removed. From the 16 cards, 4 are chosen. How many different ways are there to choose the numbers?

3. In the Lotto 535 lottery, you must choose 4 numbers from 1 to 35 and one number from 1 to 25. How many different ways are there to choose the numbers?

4. Solve for n

nP2= 12

The answer is 4 but i get 5 =3=

n!/ n-2! = 12

then i expanded and canceled out that n! leaving me (n-2)(n-1) = 12

i expanded it then i get n^2- 3n+2 = 12

i got n= 5 and -2

D:

i don't know what i did wrong.

help anyone? (: