Can you check/explain the following:
1. If you roll a number cube 66 times, how many times should you expect to roll a 1?
a. 9 times
b. 11 times
c. 8 times
d. 10 times
Ans. P(1) = favorable outcome/possible outcome
= 66/396 , (1 x 66rolls, and 6sides x 66 rolls = 396)
= 16.66%
= 17% ?? Not sure how to figure this out.
2. Thomas has a 16% chance of getting a black sticker out of a certain machine. Write this probability as a decimal and as a fraction.
a. 0.16, 4/25
b. 0.16, 8/25
c. 0.84, 42/25
d. 0.84, 21/25
Ans: A. 0.16, 4/25 ?
3. If Brian spins the spinner 40 times, how many times should he expect the spinner to land on the number 7?
Ans. This is similar to #1. But, I don't know how to solve it.
4. Harold has 3 pennies, 1 dime, and 1 nickel in his pocket. If he randomly selects one coin, what is the probability that it will be a penny?
Ans: P(penny) = 3/5 = 60%
5. Each letter in the word APPLE is written on an index card. A card is then chosen at random. What is the probability that the letter will be a L?
Ans: P(L) = 1/5 = 20%
6. A set of mugs includes 5 striped mugs, 6 plaid mugs, and 6 solid colored mugs. If one mug is to be selected, what is the probability that it is not a striped mug?
Ans: P(not stiped) = 12/17 = 71%
7. What is the probability of rolling a number less than 4 on a fair number cube? Express your answer as a fraction in simplest form.
Ans: P(less than 4) = 3/6 = 1/2
8. Jan and Tom are playing a game with a spinner. The spinner has 16 congruent sections labeled 1-16. If the number is less than 9, Jan gets a point. If the number is 9 or greater, Tom gets a point. Is the game fair? Why or why not?
Ans: Yes, this is a fair game because there are both 8 numbers less than 9 and 8 numbers >= 9.
4 answers
1. Ans: P(1) = 1/6
1/6 = x/66
x = 11 times
3. Ans: P(7) = 1/8
1/8 = x/40
x = 5 times.
Could you check the others?
5 answers