The probability of two independant events \(a\) and \(b\) can be found by multiplying the individual probabilities like so: \(P_{total} = P_a * P_b\)
For each individual probability we can find the answer via a simplfied representation:
\(P_x=\frac{desired}{total}\)
For the first stone (orange) we have:
\(P_{orange}=\frac{orange}{total}=\frac{9}{18}=\frac{1}{2}\)
For the second stone (green) we have:
\(P_{green}=\fracgreen}{total}=\frac{5}{18}\)
**(Notice that the total is still 18 since he put the first one back in the jar before drawing the second.)
So:
\(P_{total}=P_{orange} \times P_{green}\)
\(P_{total}=\frac{1}{2} \times \frac{5}{18}\)
\(P_{total}=\frac{5}{36} \approx 13.88\%\)
