Probability Problem

kidwell

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Apr 23, 2021
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There are four nickels and four dimes in your pocket. You randomly pick a coin out of your pocket and place it on a counter. Then you randomly pick another coin. The first coin is a nickel and the second coin is a dime. Find the probability.
 
There are four nickels and four dimes in your pocket. You randomly pick a coin out of your pocket and place it on a counter. Then you randomly pick another coin. The first coin is a nickel and the second coin is a dime. Find the probability.
Please show us what you have tried and exactly where you are stuck.

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Please share your work/thoughts about this problem
 
There are four nickels and four dimes in your pocket. You randomly pick a coin out of your pocket and place it on a counter. Then you randomly pick another coin. The first coin is a nickel and the second coin is a dime. Find the probability.
1/2 x 3/7 =

Am I even on the right start? Probability is my weak part and I get lost on how to figure it. So any help would be great.
 
You have eight coins in your pocket, four dimes and four nickels. What is the probability of drawing a nickel at random?

Given that you have drawn a nickel out, you now have seven coins in your pocket, four dimes and three nickels. What is the probability of drawing a dime?

Can you answer those two questions?
 
1/2 x 3/7 =

Am I even on the right start? Probability is my weak part and I get lost on how to figure it. So any help would be great.

You are off to a good start but there is a mistake in the equation you have created. Have you found that mistake?
 
This is not a hard question. So the idea is as follows. We have 4 nickels and 4 dimes and we want the probability for the event "First nickel and second dime", in terms of probability [MATH]P(N_1 \cap D_2) = P(N_1)P(D_2|N_1) = \frac{4}{4+4}\cdot\frac{4}{3+4} = \frac{4}{8}\cdot\frac{4}{7} = \frac{2}{7}[/MATH], this comes from the fact that we can draw a nickel 4 from 8 (nickel and dime) and if we have drawn a nickel than there are 7 coins left where 3 are nickel and 4 dimes.
 
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