From a bag containing 5 nickels, 8 dimes, and 7 quarters, 5 coins are drawn at random and all at once. What is the probability of getting 2 nickels, 2 dimes, and 1 quarter?

Respuesta :

Answer:

0.13

Step-by-step explanation:

From a bag containing 5 nickels, 8 dimes, and 7 quarters, 5 coins are drawn at random and all at once

we need to select 2 nickels from 5 nickels and select 2 dimes from 8 dimes and 1 quarter from 7 quarters

There are total of 5+8+7=20 coins

select 5 coins from total of 20 coins

2 nickels can be selected from 5 nickels in 5C2 ways

[tex]5C2=\frac{5!}{2!(5-2)!} =\frac{5!}{2!(3!)!}=10[/tex]

2 dimes selected from 8 dimes

[tex]8C2=\frac{8!}{2!(8-2)!} =\frac{6!}{2!(6!)}=28[/tex]

1 quarter selected from 7 quarter

[tex]7C1=\frac{7!}{1!(7-1)!} =\frac{7!}{1!(6!)}=7[/tex]

5 coins selected from 20 coins

[tex]20C5=\frac{20!}{5!(15)!} =15504[/tex]

probability of getting 2 nickels, 2 dimes, and 1 quarter

[tex]\frac{10 \cdot 28 \cdot 7}{15504} =\frac{1960}{15504} =0.13[/tex]

The probability of getting 2 nickels, 2 dimes, and 1 quarter is; 0.1264

We are given;

Number of nickels = 5

Number of dimes = 8

Number of quarters = 7

Total coins = 5 + 8 + 7

Total coins = 20

Number of ways of selecting 2 nickels will be;

N(2 nickels) = 5C2 = 10

Number of ways of selecting 2 dimes;

N(2 dimes) = 8C2 = 28

Number of ways of selecting 1 quarter;

N(1 quarter) = 7C1 = 7

Total number of ways of selecting 2 nickels, 2 dimes, and 1 quarter = 10 × 28 × 7 = 1960

Total number of coins selected out of the bag = 5

Thus;

Number of ways of selecting any 5 coins is;

N(any 5 coins) = 20C5 = 15504

Thus;

Probability of selecting 2 nickels, 2 dimes, and 1 quarter is; 1960/15504 = 0.1264

Read more on probability of selection at; https://brainly.com/question/251701