Question

Dianna has 7 quarters, 3 dimes, and 8 nickels in her purse. She reaches into her purse and randomly grabs two coins. What is the probability that Dianna grabs a dime first and then a nickel?

Answer 1

There are 18 coins total in her bag:

7+3+8=18coins

3 of the 18 coins are dimes, so the odds of first drawing a dime are 3/18

P(dime)=3/18

Since the nickel was taken out and not replaced, there are now 17 coins in her purse.

18-1=17coins

8 of the 17 remaining coins are nickels, so the odds of drawing a nickel are 8/17.

P(nickel)=8/17

Now we multiply the two probabilities by eachother to find out the odds of both occurring...

P(dime)*P(nickel)=

3/18*8/17=24/306=8/103=0.078=8%

The probability of grabbing a dime and then a nickel are 8/103 or 0.078 or an 8% chance, whichever way you'd prefer to write it.