9. If you have twice as many pennies as nickels, and the total value of these coins is the same as the value of 32 quarters, how many pennies do you have?

The answers is 228 pennies.

Step-by-step explanation:

The values of the subunits of a dollar are:

1 penny = $0.01.

1 nickel = $0.05.

1 quarter = $0.25.

If all the pennies and nickels that you have are equal to 32 quarters:

32*$0.25=$8

Now, we have twice pennies as many nickels, and x is the total amount of coins:

2x * $0.1 + $0.05x = $8

Multiply and add the terms of the equation:

$0.02x + $0.05x = $8 $0.07x = $8

Divide by $0.07 in both terms of the equation:

x = $8/$0.07 x ≅ 114 because you can have a half penny nor nickel.

When x = 114 means that you have 114 nickels and 228 pennies.

Replacing x=114

$0.02*114 + $0.05*114 = $8