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You reach into a bag of coins and withdraw two coins without replacement. What is the probability you withdrew a nickel and then a dime if the bag held five pennies, ten nickels, and four dimes?

2 Answers

2 votes
20/171







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User Bruno Kinast
by
8.9k points
5 votes

Answer:
(20)/(171)

Explanation:

Given : Number of nickels in the bag = 10

Number of dimes in the bag = 4

The total number of coins in the bag =
10+4+5=19

The probability of drawing nickel :-


\text{P(nickel)}=(10)/(19)

Total number coins left = 18

The conditional probability of drawing dime, given that a nickel is already drawn :-


\text{P(dime}|\text{nickel)}=(4)/(18)

Now, the probability you withdrew a nickel and then a dime is given by :-


\text{P(dime and nickel)}=\text{P(dime}|\text{nickel)}*\text{P(nickel)}\\\\=(10)/(19)*(4)/(18)=(20)/(171)

Now, the probability you withdrew a nickel and then a dime
}=(20)/(171)

User Daniel Kua
by
7.5k points