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
Assume that

and <span>multiply the equation

by 4p. Then you obtain the equation

.
</span>
1) If k>0, then 4pk>0 and the equation doesn't have solutions, because <span>

and this is unreal.
</span>
<span>2) If k=0, then 4pk=0 and

. There is one solution x=h.
</span>
2) If k<0, then 4pk<0 and the equation
<span>

has two different solutions

and

.</span>
<span>6∙7-3^2∙9+4^3
= 42 - 9*9 + 64
= 42 - 81 + 64
= 25
answer
25</span>