Which is __ not__ equal to 4 dimes?

4 dimes = 10¢ × 4 = 40¢

1) 6 nickels and 10 pennies=5¢ × 6+10¢=40¢

2) 5 nickels and 3 pennies= 5¢ × 5+1¢ × 3 = 28¢

3) 2 dimes and 4 nickels=10¢ ×2 +5¢ ×4= 40¢

4) 8 nickels= 5¢ × 8=40 ¢

So the answer is the second one.