how many quarters? How many nickels

Question

Kevin and Randy Muise have a jar containing 72 coins, all of which are either quarters or nickels. The total value of the coins in the jar is ?$13.40.
How many of each type of coin do they? have?

Answer 1

 

Let q = number of quarters

Let n = mumber of nickels

 

    .05n + .25q = 13.40

     n + q = 72

 

Solving by elimination method,  multiply the 2nd equation by -.04

 

     .05n + .25q = 13.40

    -.05n - .05q = -3.6

   -------------------------

               .20q = 9.8

 

                   q = 49

 

     There are 72 coins,

     72 - 49 = 23

 

There are 23 nickels and 49 quarters.