Question

A bag has 4 red 3 white 2 blue and 1 green marble in it. Use this information to answer question 9-11.

9) What is the probability pick a red or green marble?

10) Probability of getting (Red or Blue)?

11) Probability of not getting blue

A die has the numbers 1-8 on it. Use this information to solve questions 12-15.

12. What is the probability of the die landing on the number 6?

13. What is the probability of the die landing on an even number less than 5?

14. What is the probability of the die landing on a prime number?

15. What is the probability of the die landing on a number divisible by 2 or 3?

A bag has 3 white 4 red and 2 blue marbles in it.

16. How many white marbles would have to be added to make the probability of pulling a white marble be 1/2?

17. How many white marbles must be added to make the probability of choosing a white marble 2/3?​

Answer 1

Explanation:

r=4, w=3, b=2, g=1, t=(4+3+2+1)=10

9) P(r or g)=4/10+1/10=5/10= 1/2

10) P(r or b)=4/10+2/10=6/10= 3/5

11) P(!b)=P(r or w or g)=4/10+3/10+1/10=8/10= 4/5

12) There are six numbers and only one six, P(6)= 1/6

13) The only even numbers less than 5 are 2 and four so

P(e<5)=2/6= 1/3

14) The primes on a die are 2,3,5 so three primes out of six numbers

P(!)=3/6= 1/2

15) 2,3,4,6 are multiples of 2 and three

P(2n or 3n)=4/6= 2/3

16) We want a one half probability so

P(W)=(3+x)/(3+4+2+x)=1/2

(3+x)/(9+x)=1/2

2(3+x)=9+x

6+2x=9+x

x=3

So 3 white marbles have to be added.

17) (3+x)/(9+x)=2/3

3(3+x)=2(9+x)

9+3x=18+2x

x=9

So nine whites need to be added.

Answer 2

#'s 9-14

Base info: 40% are red, 30% are white, 20% are blue, and 10% are green

9) 40% chance to get red, 10% chance to get green. 50% chance to get one of either.

10) getting red: 40%

Getting blue: 20%

11) 80% (100% - 20% = 80%)

1/8 = 12.5%

12) 12.5% chance

13) 25% chance

14) 12.5 x 5 = 62.5

62.5% chance