PROBABILITY101

I have in my pocket ten coins. Nine of them are ordinary coins with equal chances of coming up head and tail when tossed and the tenth has two heads. If I take one of the coins at random from my pocket, what is the probability that it is the coin with two heads ?

• 10/10

• 1/10

• 9/10

• 1/5

10% of the bulbs produced in a factory are of red colour and 2% are red and defective. If one bulb is picked up at random, determine the probability of its being defective if it is red.

• 1/50

• 1/100

• 1/10

• 1/2

Two dice are thrown together. Let A be the event ‘getting 6 on the first die’ and B be the event ‘getting 2 on the second die’. Are the events A and B independent?

• 1/2

• 1/6

• 1/36

• 1/3

Suppose you roll two dice. What is the probability the sum is 8?

• 1/8

• 1/4

• 1/2

• 1/3

3. A family has 2 children. Given that one of the children is a boy, what is the probability that the other child is also a boy?

• 1/8

• 1/4

• 1/2

• 1/3