Question 297026
Use 0 to represent tails and 1 to represent heads.  If you flip 3 coins, the possibilities are:

0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1

As you can see, there are 8 total outcomes.

b) the chance of getting no heads would be the 0 0 0 case, which is only one of the 8 cases, so the chances are 1/8.

c) Exactly one head are the 001, 010, 100 cases which is 3/8.

d) Two heads is 011, 101, 110 which is 3/8.

e) Three heads is 111, which is 1/8.

Don't forget.  Most of the time two heads are better than one.