I believe it would be 50 nickels. 8 dollars is 800 cents and one nickel is five cents and one dime is ten cents. If you have 50 nickels, that would make 250 cents. If you also have 55 dimes, that would make 550 cents. 250 + 550 = 800, so that checks out. And 50 + 55 = 105 coins, so that checks out as well! I hope this helps, and sorry for the bad explanation! :)