Simple Probability Worksheet

**Page 1**

1.

What is the probability of selecting one blue ball from a box containing 6 blue balls?

a. | 2 | ||

b. | 3 | ||

c. | 1 | ||

d. | 4 |

[Since there are 6 blue balls in the box.]

The number of favorable outcomes is 6.

[Since there are 6 blue balls in the box.]

Probability(event) =

[Formula]

P(blue ball) =

[Substitute the values.]

The probability of selecting a blue ball is 1.

Correct answer : (3)

2.

When a number cube is rolled, what is the probability of rolling a 4?

a. | $\frac{1}{2}$ | ||

b. | $\frac{2}{3}$ | ||

c. | $\frac{1}{6}$ | ||

d. | $\frac{1}{3}$ |

Total number of outcomes = 6

Number of favorable outcomes = 1

[The only favorable outcome is 4.]

Probability(event) =

[Formula.]

P(rolling 4) =

[Substitute the values.]

The probability of rolling a 4 when a number cube is rolled is

Correct answer : (3)

3.

A coin is tossed once. What is the probability of getting a head?

a. | $\frac{1}{5}$ | ||

b. | $\frac{1}{3}$ | ||

c. | $\frac{1}{2}$ | ||

d. | $\frac{1}{4}$ |

[Head and Tail.]

Number of favorable outcomes = 1.

[1 Head is the only favorable outcome from the possible outcomes.]

P(event) =

[Formula.]

P(heads) =

[Substitute the values.]

Probability of getting a head is

Correct answer : (3)

4.

What is the probability of choosing an even number from the numbers 1, 5, 7, 9, 6, 8?

a. | $\frac{1}{4}$ | ||

b. | $\frac{1}{3}$ | ||

c. | 1 | ||

d. | $\frac{1}{2}$ |

Number of favorable outcomes is 2.

[Only 6 and 8 are even numbers.]

Probability(event) =

[Formula.]

P(even) =

[Substitute the values.]

=

[Simplify.]

The probability of getting an even number is

Correct answer : (2)

5.

What is the probability of getting an odd number when a dice is rolled?

a. | $\frac{1}{3}$ | ||

b. | $\frac{1}{2}$ | ||

c. | $\frac{1}{5}$ | ||

d. | $\frac{1}{4}$ |

Total number of outcomes when a dice is rolled is 6.

Number of favorable outcomes is 3.

[1, 3, 5 are the odd numbers.]

Probability(event) =

[Formula.]

P(getting an odd number) =

[Substitute the values.]

=

[Divide the numerator and the denominator by 3.]

Probability of getting an odd number when a dice is rolled is

Correct answer : (2)

6.

What is the probability of selecting a number, which is a multiple of 2, from the numbers 5 to 24?

a. | $\frac{7}{20}$ | ||

b. | $\frac{3}{20}$ | ||

c. | $\frac{1}{2}$ | ||

d. | $\frac{1}{24}$ |

Multiples of 2 from 5 to 24 are 6, 8, 10, 12, 14, 16, 18, 20, 22 and 24.

So, the number of favorable outcomes is 10.

Probability(event) =

[Formula.]

P(multiple of 2) =

[Substitute the values.]

Probability of selecting even numbers from numbers 5 to 24 is

Correct answer : (3)

7.

What is the probability of selecting a yellow marble from a box containing 5 yellow and 4 violet marbles?

a. | 1 | ||

b. | $\frac{4}{9}$ | ||

c. | $\frac{1}{9}$ | ||

d. | $\frac{5}{9}$ |

Number of favorable outcomes is 5.

[Since there are 5 yellow marbles.]

Probability(event) =

[Formula.]

P(yellow marble) =

[Substitute the values.]

Probability of selecting a yellow marble from 9 marbles is

Correct answer : (4)

8.

What is the probability of selecting a vowel from the word "CHRISTOPHER"?

a. | $\frac{4}{11}$ | ||

b. | $\frac{3}{11}$ | ||

c. | $\frac{1}{11}$ | ||

d. | $\frac{2}{11}$ |

So, the number of possible outcomes is 11.

Number of favorable outcomes is 3.

[I, O, E are the only vowels present in the word.]

Probability(event) =

[Formula]

P(vowels) =

[Substitute the values.]

Probability of selecting a vowel from the word "CHRISTOPHER" is

Correct answer : (2)

9.

What is the probability of drawing a nickel from a bag containing 9 dimes and 5 nickels?

a. | $\frac{1}{14}$ | ||

b. | $\frac{5}{14}$ | ||

c. | $\frac{9}{5}$ | ||

d. | $\frac{9}{14}$ |

Number of favorable outcomes = 5

[Since there are 5 nickels.]

Probability(event) =

[Formula]

P(drawing a nickel) =

[Substitute the values.]

The probability of drawing a nickel from a bag containing 9 dimes and 5 nickels is

Correct answer : (2)

10.

One letter is chosen at random from the word "MISSISSIPPI". What is the probability of choosing the letter S?

a. | $\frac{2}{11}$ | ||

b. | $\frac{3}{11}$ | ||

c. | $\frac{1}{11}$ | ||

d. | $\frac{4}{11}$ |

So, number of possible outcomes is 11.

Number of favorable outcomes is 4.

[There are 4 S's in the word "MISSISSIPPI".]

Probability(event) =

[Formula]

P(Letter S) =

[Substitute the values.]

Probability of picking S from the word "MISSISSIPPI" is

Correct answer : (4)