Question

The probability of a middle school student owning a skateboard is 0.68, of owning a bicycle is 0.72 and of owning both is 0.61. If a middle school student is chosen at random, what is the probability that the middle school student owns a skateboard or a bicycle?

Answer 1

Let:

A = the school student owns a skateboard

B = the school student owns a bicycle

`\begin{gathered} P(A)=0.68 \\ P(B)=0.72 \\ P(A\cap B)=0.61 \\ Therefore: \\ P(A\cup B)=P(A)+P(B)-P(A\cap B) \\ P(A\cup B)=0.68+0.72-0.61 \\ P(A\cup B)=0.79=79\% \end{gathered}`

Answer:

79%