A quality inspector at a valve manufacturer randomly selects one valve from each batch of fifty valves to inspect for noncompliance. The first batch of fifty valves has five non-compliant ones. The second batch of fifty valves has four non-compliant valves.

Find the probability that the inspector selects a non-compliant valve both times.

Question

A quality inspector at a valve manufacturer randomly selects one valve from each batch of fifty valves to inspect for noncompliance. The first batch of fifty valves has five non-compliant ones. The second batch of fifty valves has four non-compliant valves. 

Find the probability that the inspector selects a non-compliant valve both times.

amistre64 · Answer

p(A) = 5/50
p(B) = 4/50

p(AnB) = p(A) * p(B) in this case