Question

MAMD.M.D. 1B: A local trade unionconsists of plumbers and electricians.Classified according to rank:Apprentice JourneymanMasterPlumbers25 20 130Electricians 15 |4020A member of the union is selected at random.Given that the person selected is aplumber, the probability that he is ajourneyman is:

Answer 1

From the given table,

The total number of plumbers = (25 + 20 + 30) = 75 persons

The number of plumbers that is a journey man = 20 persons

`\text{Probability}=\frac{\text{Number of required outcomes}}{The\text{ total number of outcomes}}`
`P(\text{that he is a journeyman)=}\frac{\text{Number of plumbers that is a journey man}}{\text{The total number of plumbers}}`

`P(\text{that he is a journeyman)}=(20)/(75)=(4)/(15)`

Hence, the probability that he is a journeyman is 4/15.

Option 3 is the correct answer.