a vending machine only takes dimes and nickels. if there are 5 more nickels than dimes, and a total of $5.50. how many of each coin are there?

Question

i just really don't understand word problems and i always get it when i see it worked out.

Answer 1

Let the number of dimes be d, and the number of nickels be n

 

n = d + 5;  or  n - d = 5     (1)        (amount of coins)

 

5n + 10d = 550     or   n + 2d = 110    (2)    (amount of money all together)

 

substituting n from (1) into (2);  d + 5 + 2d = 110

 

3d = 105; or d = 105/3 = 35

 

from (1) n = 35 + 5 = 40

 

checking; 35 * 0.1 + 40 * 0.05 = 3.50 + 2.00 = 5.50