117k views
5 votes
Kevin and randy muise have a jar containing 52 coins. all of which are either quarters or nickels. the total value of coins is $6.40. how many of each coin do they have?



User BLeB
by
3.2k points

1 Answer

8 votes

Answer:

  • 19 quarters
  • 33 nickels

Explanation:

For mixture problems, it is convenient to let the variable represent the quantity of the high-value contributor.

Here, we can let x represent the number of quarters. Then the number of nickels is (52-x), and the total value of the coins is ...

0.25x +0.05(52 -x) = 6.40

0.20x +2.60 = 6.40 . . . . . . . . simplify

0.20x = 3.80 . . . . . . . . . . . subtract 2.60

x = 3.80/0.20 = 19 . . . . divide by the coefficient of x

The number of quarters is 19. The number of nickels is 52-19 = 33.

User Adrian Silvescu
by
3.4k points