You never showed the triangle
36.
Convert 10% to .1, (10 divided by 100)
then multiply 40 times .1
then subtract 4 by 40
=36
The correct answer is Choice D: 68%.
You have to make a tree diagram with all of the possibilities.
Here are the possibilities:
Rain - Win = 0.6 x 0.8 = 0.48
Rain - Loss = 0.6 x 0.2 = 0.12
No Rain - Win = 0.4 x 0.5 = 0.2
No Rain - Loss = 0.4 x 0.5 = 0.2
Adding up the two winning options gives us 68%
0.48 + 0.2 = 0.68
In order for this to be solved we need to know the angle of each side. This question cannot be solved unless you show us the Diagram. I'll be happy to help once that is settled<span />