How do you make 86 cents with only five coins?

1 quarter

3 dimes

4 nickels

1+3+4 = 8

25 + 3x10 + 4x5 = 75

1 half-dolar

2 dimes

5 pennies

1+2+5 = 8

50 + 2x10 +5x1 = 75

7 dimes

1 nickel

7+1 = 8

7x10 + 1x5 = 75