Question 451992
The total number of washers = 74+86+40 = 200
The probability that the 1st washer is steel is 86/200
Since the 1st washer is not replaced, there are 85 steel washers remaining.
So the probability that the 2nd washer is steel is 85/199
And for the 3rd, the probability is 84/198
So the total probability is:
86/200*85/199*84/198 = 0.0779