Assume his collection has 31 coins. How many dimes does he have? Demonstrate how you can solve this problem. Avoid the use of variable when possible. explain your thoght process.

Question

John has a collection of nicklels and dimes that total $2.55. Assume his collection has 31 coins. How many dimes does he have? Demonstrate how you can solve this problem. Avoid the use of variable when possible. explain your thought process.

Answer 1

N + D =31

5N+ 10D = 255

5N + 5 D = 155

5D =100

D=20 dimes

N= 11 nickels

20+11 = 31 coins

each nickel is worth 5 cents 11 nickels = 55 cents

each dime is worth ten cents 20 dimes = 2 dollars

2 dollars plus 55 cents = $2,55

20 dimes plus 11 nickels = 31 coins

or

5N +10D =255 divide by 5

N +2D = 51

N + D =31 subtract

2D- D = 51-31 = 20

D=20 dimes

N=31-20 = 11 nickels