Probability Notes

A standard dice is rolled. What is the probability that a 2, 4, OR 6 will be rolled?

• 1/2

• 1/6

• 1/3

• 2/3

A party host gives a door prize to one guest chosen at random. There are 48 men and 42 women at the party. What is the probability that the prize goes to a woman?

• 1/42

• 42/48

• 42/90

There are 15 boys and 10 girls in a class. If three students are selected at random, what is the probability that 1 girl and 2 boys are selected?

• 1/40

• 1/2

• 21/46

• 7/41

Two friends Haris and Adam appeared for an exam. Let A be the event that Haris is selected and B is the event that Adam is selected. The probability of A is 2/5 and that of B is 3/7. Find the probability that both of them are selected.

• 35/36

• 5/35

• 5/12

• 6/35

There are total 18 balls in a bag. Out of them 6 are red in colour, 4 are green in colour and 8 are blue in colour. If Amy picks three balls randomly from the bag, then what will be the probability that all the three balls are not of the same colour?

• 95/102

• 19/23

• 21/26

• 46/51

In a neighbourhood, 90% children were falling sick due flu and 10% due to measles and no other disease. The probability of observing rashes for measles is 0.95 and for flu is 0.08. If a child develops rashes, find the child’s probability of having flu.

• 0.08

• 0.167

• 0.43

• 0.072

A insurance company has insured 4000 doctors, 8000 teachers and 12000 businessmen. The chances of a doctor, teacher and businessman dying before the age of 58 is 0.01, 0.03 and 0.05, respectively. If one of the insured people dies before 58, find the probability that he is a doctor.

• 1/22

• 1/3

• 3/22

• 2/3