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A jar contains 6 chocolate chip cookies and 9 peanut butter cookies. Richard grabs 3 cookies at random to pack in his lunch. What is the probability that he drew 2 chocolate chip cookies and 1 peanut butter cookie?

A.
(1)/(54)

B.
(1)/(27) }

C.
(9)/(91) }

D.
(27)/(91) }

2 Answers

4 votes
Here, Your Answer would be 9/91

In short, Answer is Option C

Hope this helps!
User Miboper
by
5.9k points
2 votes

Answer: D.
(27)/(91)

Explanation:

Given: Number of chocolate chip cookies - 6

Number of peanut butter cookie = 9

Total cookies = 6+9=15

The total number of combinations of selecting 3 cookies from 15 cookies


^(15)C_3=(15!)/((15-3)!3!)=455

The number of combinations to select 2 chocolate chip cookie=


^(6)C_2(6!)/((6-2)!2!)=15

The number of combinations to select 1 peanut butter cookie=


^(9)C_1=(9!)/((9-1)!1!)=9

The probability that he drew 2 chocolate chip cookies and 1 peanut butter cookie=
(^(9)C_1* ^(9)C_1)/(^(15)C_3)=(15*9)/(455)=(27)/(91)

User Natsume
by
6.5k points