A box contains 81 coins, only dimes and nickels. The amount of money in the box is $5.30. How many dimes and how many nickels are in the box?
+33614 "A box contains 81 coins, only dimes and nickels. The amount of money in the box is $5.30. How many dimes and how many nickels are in the box?"
d + n = 81 (1)
10d + 5n = 530 divide by 5 to get 2d + n = 106 (2)
Subtract (1) from (2): d = 106 - 81 = 25 (3)
Use (3) in (1): 25 + n = 81 or n = 81 - 25 = 56
There are 25 dimes and 56 nickels.
+36915 x = nickels value = 5x
(81-x) = dimes value = 10 (81-x) summed, the values = 530
5x + 10(81-x) = 530 solve for 'x' ..the number of nickels then dimes = 81-x
