1.
What is probability?
Correct Answer
B. A way of expressing knowledge or belief that an event will occur or has occurred
Explanation
Probability is a mathematical concept used to express the likelihood or chance of an event occurring. It is not a method of counting objects or predicting future events, but rather a way of quantifying our knowledge or belief about the likelihood of an event happening or having already occurred. It allows us to assign a numerical value to the likelihood of an event, ranging from 0 (impossible) to 1 (certain).
2.
The menu at a restaurant has 3 drinks, 4 appetizers, and 5 main courses. How many different meals are possible?
Correct Answer
C. 60
Explanation
The number of different meals that are possible can be calculated by multiplying the number of options for each category. In this case, there are 3 options for drinks, 4 options for appetizers, and 5 options for main courses. Therefore, the total number of different meals that can be created is 3 x 4 x 5 = 60.
3.
On a game show, the game that a contestant plays is chosen by spinning a spinner. The spinner has 5 colors on it: red, green, blue, purple, and orange.
What is the complement of spinning a red or orange on this spinner? (Remember: complement = NOT)
Correct Answer
C. Green, purple, blue
Explanation
The complement of spinning a red or orange on the spinner would be the remaining colors on the spinner, which are green, purple, and blue.
4.
John has a bag of marbles. In the bag, there are 4 yellow marbles, 7 red marbles, and 3 green marbles. What is the probability that John will pull out a yellow marble?
Correct Answer
4/14 , 2/7
Explanation
The probability of pulling out a yellow marble can be calculated by dividing the number of yellow marbles in the bag by the total number of marbles. In this case, there are 4 yellow marbles out of a total of 14 marbles. Therefore, the probability of pulling out a yellow marble is 4/14.
5.
When a die is rolled, what is the complement of getting an odd number?
Correct Answer
A. Getting an even number
Explanation
The complement of an event refers to all the outcomes that are not part of that event. In this case, the event is getting an odd number when a die is rolled. The possible outcomes when rolling a die are 1, 2, 3, 4, 5, and 6. Out of these, the odd numbers are 1, 3, and 5. Therefore, the complement of getting an odd number would be getting an even number, which includes 2, 4, and 6.
6.
There are 20 girls and 35 boys in the lunch room. What is the probability of choosing a boy to sit with?
Correct Answer
35/55
Explanation
The probability of choosing a boy to sit with can be calculated by dividing the number of boys by the total number of students in the lunch room. In this case, there are 35 boys and a total of 55 students (20 girls + 35 boys). Therefore, the probability of choosing a boy to sit with is 35/55.
7.
There are 52 cards in a deck. What is the probability of choosing a jack?
Correct Answer
4/52
Explanation
The probability of choosing a jack can be calculated by dividing the number of favorable outcomes (4 jacks in a deck) by the total number of possible outcomes (52 cards in a deck). Therefore, the probability is 4/52.
8.
There are 10 pencils, 3 pens, and 14 markers in a bin. What is the probability of choosing a pen and a pencil?
Correct Answer
B. 10/243
Explanation
To find the probability of choosing a pen and a pencil from the bin, you can use the concept of probability. The probability of two independent events occurring together is found by multiplying the probabilities of each event.
Probability of choosing a pen:
There are 3 pens in the bin.
The total number of items in the bin is 10 (pencils) + 3 (pens) + 14 (markers) = 27 items.
Probability of choosing a pen = (Number of pens) / (Total number of items) = 3 / 27 = 1/9.
Probability of choosing a pencil:
There are 10 pencils in the bin.
The total number of items in the bin is still 27 items.
Probability of choosing a pencil = (Number of pencils) / (Total number of items) = 10 / 27.
Now, to find the probability of both events happening together (choosing a pen and a pencil), you multiply the individual probabilities:
Probability of choosing a pen and a pencil = (1/9) * (10/27) = 10/243.
So, the probability of choosing a pen and a pencil from the bin is 10/243.
9.
There are 52 cards in a deck. What is the probability of choosing a jack and a king?
Correct Answer
A. 16/2704
10.
There are 34 kittens, 12 dogs, and 15 birds at a pet store. What is the probability that a customer will purchase a dog?
Correct Answer
12/61
Explanation
The probability of purchasing a dog is calculated by dividing the number of dogs by the total number of animals in the pet store. In this case, there are 12 dogs out of a total of 34 kittens, 12 dogs, and 15 birds. Thus, the probability is 12/61.
11.
A coin is tossed. What is the probability of getting heads?
Correct Answer
1/2
Explanation
When a coin is tossed, there are two possible outcomes: heads or tails. Since there are only two equally likely outcomes, the probability of getting heads is 1 out of 2, or 1/2.
12.
A die is rolled. What is the complement of rolling a 5?
Correct Answer
B. Rolling a 1, 2, 3, or 4
Explanation
The complement of an event refers to all the outcomes that are not part of that event. In this case, the event is rolling a 5. The complement of rolling a 5 would be rolling any number other than 5, which includes rolling a 1, 2, 3, or 4.
13.
There are 6 pink, 2 blue, and 8 green socks in a drawer. What is the probability of the complement of picking a pink sock? (Remember: complement = NOT)
Correct Answer
C. 10/16
Explanation
The probability of picking a pink sock is 6/16. The complement of picking a pink sock would be picking any sock that is not pink, which includes the blue and green socks. There are a total of 2 blue socks and 8 green socks, making a total of 10 socks that are not pink. Therefore, the probability of the complement of picking a pink sock is 10/16.
14.
Jason has a bag full of coins. There are 12 dimes, 21 pennies, 13 nickels, and 7 quarters in his bag. If he chooses a coin at random, what is the probability that he chooses either a quarter and a dime?
Correct Answer
D. 19/53
Explanation
The probability of choosing a quarter is 7/53 (since there are 7 quarters out of a total of 53 coins), and the probability of choosing a dime is 12/53 (since there are 12 dimes out of a total of 53 coins). To find the probability of choosing either a quarter or a dime, we add the probabilities together: 7/53 + 12/53 = 19/53. Therefore, the correct answer is 19/53.
15.
Sarah has 4 tomatoes, 3 potatoes, and 5 apples in her bag. What is the probability of the complement of her eating a tomato? (Remember: complement = NOT)
Correct Answer
A. 8/12
Explanation
The probability of the complement of Sarah eating a tomato can be calculated by subtracting the probability of her eating a tomato from 1. Since Sarah has 4 tomatoes and a total of 12 fruits (4 tomatoes + 3 potatoes + 5 apples), the probability of her eating a tomato is 4/12. Therefore, the probability of the complement is 1 - 4/12, which simplifies to 8/12.
16.
Katherine has 7 shirts, 3 pairs of pants, and 4 pairs of socks. How many different outfits can she make?
Correct Answer
B. 84
Explanation
Katherine can make different outfits by combining each shirt with each pair of pants and each pair of socks. Since she has 7 shirts, 3 pairs of pants, and 4 pairs of socks, the total number of different outfits she can make is 7 x 3 x 4 = 84.