Probability Math Question

Thanks, guys.

b i think

0.185+0.306=0.491 (C)

P (I or O) = P(I)  + P(O)   - P(I and O)

The probability  of  I and O   = 0  (since the arrow can't land two places at once)...so we have..

P (I or O) = P(I)  + P(O)   =

                 0.185   + 0.306  =     0.491

everything is calculating on 100 % there is only one thing

9.2% bull s eye

18.5% inner ring 

30.6%outer ring

41.7%miss