Question 3 (30 points)
i)- An electrical appliance retailer sells three brands of washers, and their market shares are respectively
50%, 30%, 20%. It is estimated that 2.5% of brand 1's, 2% of brand 2's, and 1% of brand 3's washer will
be returned by customers for repair while under the one-year warranty offered by manufacturers.
a) Find the probability that a sold washer is of brand $i$ ($i = 1, 2, 3$)?
b) Find the probability that a washer requires warranty repair work given that it is of brand $i$?
c) Find the probability that a random customer purchases a brand 1's washer and has to return it to the
retailer for repair covered by the one-year warranty?
d) Find the probability that a washer sold by the retailer will be returned for warranty repair?
