Question 1138104
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There are 3 red out of 8 total in the smaller wheel. 
The probability of spinning on red for this wheel is 3/8


There are 4 red out of 12 total in the larger wheel. 
The probability of spinning on red for this wheel is 4/12 = 1/3


Your book states "Assuming that the wheels are independent" meaning that one wheel does not affect the other. The two events being independent allows us to multiply the probabilities found earlier.


M = event of spinning red on the smaller wheel
N = event of spinning red on the larger wheel
P(M) = 3/8
P(N) = 1/3
P(M and N) = probability of getting red on both wheels
P(M and N) = P(M)*P(N)
P(M and N) = (3/8)*(1/3)
P(M and N) = (3*1)/(8*3)
P(M and N) = 3/24
P(M and N) = 1/8


Answer as a fraction: <font color=red size=4>1/8</font>


Extra info: This is equivalent to the decimal form 0.125 which converts to 12.5%
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