Question

What is the probability that a randomly chosen injured skater was age 12 or was wearing in line skates ?

Answer 1

Formula for probability is given below as,

`\text{Probability = }\frac{required\text{ outcomes}}{possibl\text{e ourcomes}}`
`\begin{gathered} \text{Prob that a skater aged 12 is injured should be taken as P(L)} \\ P(L)=0.9 \\ \text{Prob that a skater is wearing in-line skates be taken as P(M)} \\ P(M)=0.2 \\ \text{Prob that a skater is aged 12 and wearing in-line skates is P(N)} \\ P(L\text{ AND M) = 0.1} \end{gathered}`

To find the probability that an injured skater was age 12 or wearing an in-line skates will be,

`\begin{gathered} P(L\text{ OR M) =P(L) + P(M) - P(L AND M)} \\ \end{gathered}`

Substituting all the probabilities into the question above,

`P(L\text{ OR M) =0.9 + 0.2 - 0.1 = 1}`

Hence, the answer is 1.