14*2 would be calculated first
R - it is rain (probablity: 0.86)
N - it is not rain (probablity: 1-0.86 = 0.14)
You've got these cases:
R R R R R R R R R N
R R R R R R R R N R
R R R R R R R N R R
. . .
N R R R R R R R R R - it is 10 cases. Probablity each case is
(0.86)^9 * 0.14 - it is approximately 0.036 (9R and 1N - you multiply everything)
It is 10 cases so you have to multiply by 10 and you get 0.36
There is also eleventh case:
R R R R R R R R R R
Probablity is (0.86)^10 approximately 0.22
Add these cases and you'll get your probablity: 0.36 + 0.22 = 0.58