Question

At the end of each day, helen throws all the change from her purse into a box. the box contains only pennies, nickels, and dimes. at the end of one week she found that the total value of the coins was $6.43. if the number of dimes was 3 more than the number of nickels and the number of pennies was 5 more than the number of nickels, how many dimes were in the box?

Answer 1

If you subtract the value of the extra dimes and pennies, you have groups of coins consisting of 1 dime, 1 nickel, and 1 penny, worth 16¢. The value of this reduced collection is $6.43 -0.35 = $6.08. That is the value of
.. 6.08/.16 = 38 . . . . groups of coins.

There were 38 +3 = 41 dimes in the box.