Question

A box consists of 60 wall clocks, out of which 40 are good, 15 have minor defects and the remaining are broken. A trader will reject the box, if the clock taken out from the box is broken. The trader randomly takes out one clock from the box. What is the probability that:

1. the box will be rejected? 
2. the clock taken out of the box has minor defect?

Answer 1

Given:

Total wall clocks = 60

Good clocks = 40

Clocks with minor defects = 15

Broken clocks = 60 – (40 + 15)

= 60 – 55

= 5

i. Probability that the box will be rejected:

The box is rejected if the clock is broken.

P(Rejected) = `"Number of broken clocks"/"Total clocks"`

P(Rejected) = `5/60 = 1/12`

ii. Probability of minor defect:

P(Minor defect) = `"Number of clocks with minor defects"/"Total clocks"`

P(Minor defect) = `15/60 = 1/4`