Question

1) Find the probability of not drawing a four of diamonds.
2) Find the probability of not drawing a spade
3) Blue Productions supplies Blu-ray discs in lots of 72. Blue Productions know that their Blu-ray discs have a reported defect rate of 0.3%.Find the probability of getting at least one defective disc in a lot of 72?

Answer 1

1)

Required probability = P(not drawing a four of diamonds) = 1 - P(drawing a four of diamonds)

=

{Since in a deck of 52 cards, there is only 1 four of diamonds}

2)

Required probability = P(not drawing a spade) = 1 - P(drawing a spade)

=

{Since in a deck of 52 cards, there 13 spades}

3)

Let X denote the number of defective discs in the lot. Then

Required probability =