Dogs are inbred for such desirable characteristics as color; but an unfortunate by-product of such inbreeding can be the emergence of characteristics such as deafness. A 1992 study of bull terriers (by Strain and others, as reported inThe Veterinary Journal) found the following:

(i)50% of the studied bull terriers are white.

(ii)11% of the studied bull terriers are deaf.

(iii)20%

of the white bull terriersare deaf.

What is the probability that a randomly chosen bull terrier is whiteand deaf?

a..11 / .50 = .22

b..20 / .50 = .4

c..11 / .20 = .55

d..50 * .11 = .055

e..50 * .20 = .1

f..11 * .20 = .022