In this worksheet, we will practice finding the probability of a simple event.

Q1:

A class contains 6 boys and 21 girls.
What is the probability of selecting a girl if a student is selected at random?

A

B

C

D

E

Q2:

What is the probability of rolling an odd number on a fair die?

A

B0

C

D

Q3:

A bag contains 7 white marbles, 8 black marbles, and 7 red marbles. If a marble is chosen at random from the bag, what is the probability that it is white?

A

B

C

D

Q4:

What is the probability of selecting at random a prime number from the numbers
8, 9,
20, 19,
3, and 15?

A

B0

C

D1

E

Q5:

A card is drawn from a deck of cards numbered from 1 to 37. What is the probability that the number on the card is even?

A

B

C1

D

E

Q6:

The table shows the results of a survey that asked 30 students to vote for their favourite sport.

Sport

Football

Basketball

Volleyball

Swimming

Number of Students

12

9

3

6

What is the probability that a randomly selected student voted for basketball?

A

B

C

D

Q7:

A card is selected at random from a pack of 45 cards which
are numbered 1 to 45. What is the
probability that the selected card has a perfect square number?

A

B

C

D

E

Q8:

A card is drawn from a deck of cards numbered 1 to 30. Find the probability of getting a card with a positive integer less than 20 on it.

A

B

C

D

Q9:

A bag contains 24 white balls and an unknown number of red
balls. The probability of choosing at random a red ball is . How many balls are there in the bag?

Q10:

A bag contains an unknown number of marbles. There are 2 red marbles, some white marbles, and some black marbles.
The probability of getting a white marble is , and the probability of getting a black marble is .
Calculate the number of marbles in the bag.

This lesson includes 19 additional questions and 209 additional question variations for subscribers.