The probability of 2 heads:
105:500
This can be simplified further. If you divide them both by 5, you get:
21:100
That is the answer, as it cannot be simplified any further.
The probability of one head:
275:500
This can be simplified further. If you divide them both by 25, you get:
11:20
That is the answer, as it cannot be simplified any further.
The probability of no heads:
120:500
This can be simplified further. If you divide them both by 20 you get:
6:25
That is the answer, as it cannot be simplified any further.
So:
a) 21:100
b) 11:20
c) 6:25
