Introduction to Probability

1. You roll a fair 6 -sided die.

What is $\mathrm{P}$ (roll a 2)?

If necessary, round your answer to $2$ decimal places.

__________

2. Greg has an MP3 player called the Jumble. The Jumble randomly selects a song for the user to listen to. Greg's Jumble has $6$ classical songs, $7$ rock songs, and $9$ rap songs on it.

What is $\mathrm{P}$ (not a rap song)?

If necessary, round your answer to 2 decimal places.

__________

3. You draw a card at random from a deck that contains $3$ black cards and $7$ red cards.

What is $\mathrm{P}($ draw a black card $)$ ?

If necessary, round your answer to 2 decimal places.

__________

4. You spin the spinner shown below once. Each sector shown has an equal area.

What is $\mathrm{P}$ (beaver)?

If necessary, round your answer to 2 decimal places.

__________

5. You randomly draw a marble from a bag of marbles that contains $8$ blue marbles, $5$ green marbles, and $8$ red marbles.

What is $\mathrm{P}$ (draw a blue or red marble)?

If necessary, round your answer to 2 decimal places.

__________

6. Omar ordered his sister a birthday card from a company that randomly selects a card from their inventory. The company has $21$ total cards in inventory. $14$ of those cards are birthday cards.

What is $\mathrm{P}$ (not a birthday card)?

If necessary, round your answer to 2 decimal places.

__________

7. You spin the spinner shown below once. The spinner has $4$ equal sectors colored pink, purple, blue, and green.

What is $\mathrm{P}$ (blue)?

If necessary, round your answer to 2 decimal places.

__________

1. $\mathrm{P}($ roll a 2$)=\frac{1}{6} \approx 0.17$

2. $\mathrm{P}($ not a rap song $)=\frac{13}{22} \approx 0.59$

3. $\mathrm{P}($ draw a black card $)=\frac{3}{10}=0.3$

4. $\mathrm{P}($ beaver $)=\frac{1}{3} \approx 0.33$

5. $\mathrm{P}($ draw a blue or red marble $)=\frac{16}{21} \approx 0.76$

6. $\mathrm{P}($ not a birthday card $)=\frac{7}{21} \approx 0.33$

7. $\mathrm{P}($ blue $)=\frac{1}{4}=0.25$

1. Tomer owns a daycare center called Kidz Kare. One afternoon he collected the age of each person in Kidz Kare. The following histogram summarizes the data he collected.

Based on this data, what is a reasonable estimate of the probability that the next person to enter Kidz Kare is between 10 and 15 years old?

Choose the best answer.

Choose 1 answer:

(A) $\frac{2}{10}$

(B) $\frac{2}{7}$

(C) $\frac{3}{10}$

(D) $\frac{3}{7}$

2. The table shows the number of feathers Patsy the Peacock sold at each of the 8 festivals this year.

$\begin{array}{|c|c|c|c|}\hline 3 & 6 & 1 & 4 \\\hline 2 & 3 & 7 & 2 \\\hline\end{array}$

Based on this data, what is a reasonable estimate of the probability that Patsy sells fewer than 5 feathers next festival?

Choose the best answer.

Choose 1 answer:

(A) $25 \%$

(B) $46 \%$

(C) $54 \%$

(D) $75 \%$

3. Coach Kelly documented the number of points the Ragin' Cajun football team scored each game this season. The following histogram summarizes the data.

Based on this data, what is a reasonable estimate of the probability that the Ragin' Cajun score 30 or more points in their next football game?

Choose the best answer.

Choose 1 answer:

(A) $\frac{5}{16}$

(B) $\frac{3}{11}$

(C) $\frac{5}{11}$

(D) $\frac{3}{16}$

4. So far, $907$ of the $1223$ voters have agreed to the new amendment.

Based on this data, what is a reasonable estimate of the probability that the next voter does not agree to the new amendment?

Choose 1 answer:

(A) $\frac{1223}{2130}$

(B) $\frac{907}{1223}$

(C) $\frac{316}{1223}$

(D) $\frac{316}{907}$

5. The following frequency table summarizes this year's injuries on the Canadian Rounders cricket team.

$\begin{array}{cc}\text { Number of injured players } & \text { Number of matches } \\\hline 0 & 4 \\\hline 1 & 5 \\\hline 2 & 2 \\\hline 3 & 3 \\\hline 4 & 2 \\\hline\end{array}$

Based on this data, what is a reasonable estimate of the probability that the Canadian Rounders have 0 players injured for their next match?

Choose the best answer.

Choose 1 answer:

(A) $20 \%$

(B) $25 \%$

(C) $33 \%$

(D) $40 \%$

6. The Cinemania theater showed $108$ different movies last year. Of those, $15$ movies were action movies.

Based on this data, what is a reasonable estimate of the probability that the next movie is an action movie?

Choose 1 answer:

(A) $\frac{93}{108}$

(B) $\frac{15}{108}$

(C) $\frac{108}{93}$

(D) $\frac{15}{93}$

7. The following frequency table summarizes last week's bed sales at Cloud Nine Furniture.

$\begin{array}{cc}\hline \text { Size of bed } & \text { Number of beds } \\\hline \text { Twin } & 3 \\\hline \text { Double } & 6 \\\hline \text { Queen } & 4 \\\hline \text { King } & 2 \\\hline \end{array}$

Based on this data, what is a reasonable estimate of the probability that the next bed sold is a twin bed?

Choose the best answer.

Choose 1 answer:

(A) $0.20$

(B) $0.25$

(C) $0.27$

(D) $0.40$

1. The probability that the next person to enter Kidz Kare is between $10$ and $15$ years old is $\frac{3}{10}$.

2. The probability that Patsy sells fewer than $5$ feathers next festival is $75 \%$.

3. The probability that the Ragin' Cajun score $30$ or more points in their next football game is $\frac{5}{16}$.

4. The probability that the next voter does not agree to the new amendment is $\frac{316}{1223}$.

5. The probability that the Canadian Rounders have $0$ players injured for their next match is $25 \%$.

6. The probability that the next movie is an action movie is $\frac{15}{108}$.

7. The probability that the next bed sold is a twin bed is $0.20$.

1. Marvin Martian, Aly Alien, and Hank Human are all looking for a hidden spaceship. Their probabilities of finding the spaceship first are as follows:

$\begin{aligned}&\mathrm{P} \text { (Marvin wins })=30 \% \\&\mathrm{P} \text { (Aly wins })=0.2 \\&\mathrm{P} \text { (Hank wins })=\frac{1}{2}\end{aligned}$

Put the following events in order from least to most likely.

2. Ahmed and Gavin are playing both chess and checkers. The probability of Ahmed winning the chess game is $45 \%$. The probability of Ahmed winning the checkers game is $0.36$.

Which of these events is more likely?

Choose 1 answer:

(A) Ahmed wins the chess game.

(B) Ahmed wins the checkers game.

(C) Neither. Both events are equally likely.

3. Carl is wondering if the train he is riding home from school will leave early, on time, or late. The probabilities are as follows:

$\mathrm{P}($ Train leaves early $)=25 \%$

$\mathrm{P}($ Train leaves on time $)=0.35$

$\mathrm{P}($ Train leaves late $)=\frac{2}{5}$

Put the following events in order from least to most likely.

4. Simone is stranded on an island. The probability of her finding safety by waiting for help is $\frac{1}{4}$. The probability of her finding safety by leaving in her raft is $0.32$.

Which of these events is more likely?

Choose 1 answer:

(A) Simone finds safety by waiting for help.

(B) Simone finds safety by leaving in her raft.

(C) Neither. Both events are equally likely.

5. Erin, Elizabeth, and Anna are playing a game. Their probabilities of winning the game are as follows:

$\mathrm{P}($ Erin wins $)=0.3$

$\mathrm{P}($ Anna wins $)=\frac{1}{2}$

$\mathrm{P}($ Elizabeth wins $)=20 \%$

Put the following events in order from least to most likely.

6. The probability of Jamie making money investing in bonds is $\frac{1}{20}$. The probability of Jamie making money investing in stocks is $82 \%$.

Which of these events is more likely?

Choose 1 answer:

(A) Jamie makes money investing in bonds.

(B) Jamie makes money investing in stocks.

(C) Neither. Both events are equally likely.

7. Victor has been wrongfully accused of helping a gorilla escape from the zoo. The probabilities of the court rulings are as follows:

$\begin{aligned}&\mathrm{P}(\text { Guilty })=0.25 \\&\mathrm{P}(\text { Innocent })=55 \% \\&\mathrm{P}(\text { Retrial })=\frac{1}{5}\end{aligned}$

Put the following events in order from least to most likely.