A jewellery supplier has a supply of pairs of earrings of which 10% are platinum pairs. A jewellery store orders five sets of earrings from this supplier. If the supplier selects the pairs of earrings at random, what
Is the chance that the jewellery store gets exactly two sets of platinum pairs?
A) 0.3645
B) 0.0405
C) 0.0729
D) 0.0030

Question

Quizplus · Accepted Answer

The probability of getting a platinum pair is 10%, which means the probability of not getting a platinum pair is 90%. We need to use the binomial probability formula to find the probability of getting exactly two platinum pairs in five sets of earrings.

P(exactly 2 platinum pairs) = (5 choose 2) * (0.1)^2 * (0.9)^3
= (10) * (0.01) * (0.729)
= 0.0729

Therefore, the chance that the jewellery store gets exactly two sets of platinum pairs is 0.0729 or 7.29%. The correct answer is C.

A Jewellery Supplier Has a Supply of Pairs of Earrings