Question

Tony has a bag of 10 quarters, 12 nickels, and 8 dimes. Tony selects a coin, records it, then replaces it back in the bag before choosing again.

Find the probability he selects a quarter first, dime second, and nickel

third. Write your answer in a fraction in simplest form.


Please help me!!

Answer 1

8/225

Explanation:

The probability of each event would be the number of the type of currency that you have specified divided by the total number of coins, in this case the total amount of coins does not change as the coin returns to the bag.

The total number of coins is: 10 + 12 + 8 = 30

The probability of finding a quarter is:

10/30

The probability of finding dime is:

8/30

The probability of finding nickel is:

12/30

The final probability then is:

(10/30) * (8/30) * (12/30) = 960/27000

If we simplify this, dividing both numbers by 120, we are left with:

8/225