First, let's work with the denominator alone:
4⁻⁴ = 1 / 4⁴ = 1/256 .
The original problem is the reciprocal of that = 256.
The first question is the second answer
This is actually easy, because you just have to add up the 25 +15 and that would get you 40. Then you would have to add 20 to the 40 and that would be 60, so that would make 40/60 chance that she wouldn't get blue.
And if you need it in a percentage, then you can just convert this into a percentage which would be, 66.666666666667%, also known as 66.67%
