# Probability Practice Worksheets

Probability Practice Worksheets
• Page 1
1.
Express verbally the probability of selecting a nickel from a box which contains quarters, nickels, dimes and pennies.

 a. 4 out of 10 b. 1 out of 10 c. 5 out of 10 d. 3 out of 10

#### Solution:

There are 10 possible outcomes.

There are 3 nickels.

So, the probability of selecting a nickel is 3 out of 10.

2.
What is the probability of getting a sum of 10 when two dice are rolled?
 a. $\frac{1}{18}$ b. $\frac{1}{12}$ c. $\frac{1}{36}$ d. $\frac{1}{9}$

#### Solution:

Total number of possible outcomes when two dice are rolled = 62 = 36.
[Each dice has 6 faces.]

Total number of favorable outcomes to get a sum of 10 is 3.
[The favorable outcomes are (6, 4), (5, 5), (4, 6).]

Probability(event) = Number of favorable outcomesNumber of possible outcomes
[Formula.]

P(sum of 10) = 3 / 36
[Substitute the values.]

= 3 ÷ 336 ÷ 3 = 112
[Simplify.]

The probability of getting a sum of 10 when two dice are rolled is 1 / 12.

3.
Express the probability of picking a yellow colored shape by using a fraction.

 a. $\frac{3}{31}$ b. $\frac{4}{31}$ c. $\frac{28}{31}$ d. $\frac{1}{31}$

#### Solution:

There are 31 possible outcomes.

There are 4 yellow colored shapes.

So, the probability of picking a triangle is 4 / 31.

4.
A basket contains different fruits as shown. Verbally express the probability of picking a strawberry.

 a. 1 out of 16 b. 15 out of 16 c. 7 out of 16 d. 3 out of 16

#### Solution:

There are 16 possible outcomes.

There are 3 strawberries in the basket.

So, the probability of picking a strawberry is 3 out of 16.

5.
A single card is chosen at random from a standard deck of 52 cards. What is the probability that the card chosen is a Jack?
 a. $\frac{1}{3}$ b. $\frac{3}{52}$ c. $\frac{1}{13}$ d. $\frac{1}{8}$

#### Solution:

Total number of possible outcomes is 52.

Number of favorable outcomes is 4.

Probability(event) = Number of favorable outcomesNumber of possible outcomes
[Formula.]

P(a Jack) = 4 / 52 = 1 / 13
[Substitute the values and simplify.]

The probability that the card chosen is a Jack is 1 / 13.

6.
A cube is chosen at random from 11 blue cubes in a bag. What is the probability of getting a blue cube?
 a. $\frac{1}{11}$ b. $\frac{1}{2}$ c. 1

#### Solution:

There are 11 possible outcomes.

Since all the cubes in the bag are blue, the number of favorable outcomes is 11.

Probability of an event = Number of favorable outcomesNumber of possible outcomes
[Formula.]

P(blue cube) = 11 / 11
[Substitute the values.]

= 1
[Divide.]

The probability of getting a blue cube is 1.

7.
There are 14 coins in Henry's pocket. What is the probability of Henry choosing one out of them?
 a. 14 b. $\frac{1}{14}$ c. $\frac{1}{2}$ d. 1

#### Solution:

Number of possible outcomes = 14

Number of favorable outcomes = 1

P (coin) = Number of favorable outcomesNumber of possible outcomes

= 1 / 14
[Substitute the values.]

So, the probability of Henry choosing a coin from his pocket is 1 / 14.

8.
6 white, 5 red and 8 yellow roses are arranged in a flower vase. Use a fraction to express the probability of picking a red rose from the flower vase.
 a. $\frac{8}{19}$ b. $\frac{1}{19}$ c. $\frac{5}{19}$ d. $\frac{6}{19}$

#### Solution:

Number of possible outcomes = 19
[Add the number of white, red and yellow flowers in the vase.]

Number of favorable outcomes = 5
[There are 5 red roses in the vase.]

So, the probability of picking a red rose is 5 / 19.

9.
What is the probability of choosing a green marble from a bag containing 16 red marbles and 16 green marbles?
 a. $\frac{1}{3}$ b. $\frac{1}{4}$ c. $\frac{1}{2}$ d. $\frac{1}{5}$

#### Solution:

Number of possible outcomes = 32

Number of favorable outcomes = 16

Probability (green marble) = Number of favorable outcomesNumber of possible outcomes

= 16 / 32 = 1 / 2
[Divide.]

So, the probability of choosing a green marble from the bag is 1 / 2.

10.
A teacher chooses a student at random from a class of 58 girls. What is the probability that the student chosen is a girl?
 a. 1 b. $\frac{1}{2}$ c. $\frac{1}{30}$

#### Solution:

Number of possible outcomes = 58

Since all the students in the class are girls, number of favorable outcomes is 58.

Probability of an event = Number of favorable outcomesNumber of possible outcomes
[Formula.]

P (girl) = 58 / 58 = 1
[Substitute the values.]

The probability that the student chosen is a girl is 1.