Question

Kevin and Randy Muise have a jar containing 70 coins, all of which are either quarters or nickels. The total value of the coins in the jar is $7.50. How many of each type of coin do they have.​

Answer 1

Answer:

50 nickels, 20 quarters.

Step-by-step explanation:

System of equations (q = # of quarters, n = # of nickels):

q + n = 70, 0.25q + 0.05n = 7.50

the first equation can be changed to q = 70 - n, so we are able to substitute q with 70 - n.

So, it will look like 0.25*70 - 0.25n + 0.05n = 7.50. This can be simplified to 0.2n = 10, which means that n = 50.

Knowing that we can solve q + 50 = 70, which means that q = 20.