A Box Contains 20 Widgets, 4 of Which Are Defective $\frac { 1 } { 4845 } ; \frac { 364 } { 969 }$

Multiple Choice

A box contains 20 widgets, 4 of which are defective. If 4 are sold at random, find the probability that (a) all aredefective (b) none are defective.

A) $\frac { 1 } { 4845 } ; \frac { 364 } { 969 }$
B) $\frac { 1 } { 5 } ; \frac { 4 } { 5 }$
C) $\frac { 1 } { 116,280 } ; \frac { 1 } { 29,070 }$
D) $\frac { 1 } { 20 } ; \frac { 1 } { 5 }$