How do you get $1.50 with quarters, dimes, nickels and pennies using seven coins?

This is not possible without also using a half-dollar coin. Using only quarters, dimes, nickels and pennies, $1.50 can be made with six or eight coins, but not with seven.

Using six quarters would create a total of $1.50. With only five quarters, the total would be $1.25. This requires coming up with the additional 25 cents using two coins that are not quarters. The highest value that could be achieved is 20 cents using two dimes, thus the task is impossible. It becomes possible if the half-dollar coin is introduced. The solution is then one half-dollar, three quarters, two dimes and one nickel.