Question 1071381
There are 16 possible outcomes with the following distribution of number of heads,
0H : 1
1H : 4
2H : 6
3H : 4
4H : 1
So,
{{{P(H=1)=4/16=1/4}}}
{{{P(H>=1)=(4+6+4+1)/16=15/16}}}