kevin and randy muise have a jar containing 38 coins all of which are either quarters or nickels. the total of the coins in the jar is $5.70. how many of each type of coin do they have?

Answer 1

We set up this problem differently if we are working with one variable or two.

If we are working with one variable, we say that we have

Q quarters and 38 - Q nickels.

Our total in the jar is 25 Q + 5 ( 38 - Q) = 25 Q + 190 - 5 Q

25 Q + 190 - 5 Q = 570

20 Q = 380

Q = 19

nickels = 38 - 19 = 19

19 quarters and 19 nickels

If you are using two variables, you would let N = nickels

Q + N = 38 (coins)

25Q + 5N = 570 (total)

5Q + 5N = 190

subtracting, 20Q = 380

Q = 19

substituting, 19 + N = 38

N = 19