Question

every evening Jenna empties her pockets and puts her change in a jar. At the end of the week she counts her money. One week she had 38 coins, all of them being quarters and dimes. When she added them up she had a total of $6.95. Let d=number of dimes and q= number of quarters. How many dimes did Jenna have?

Answer 1

d = dimes

q = quarters

d+q = 38 coins

q=38-d

0.25q + 0.10d=6.95

0.25(38-d)+0.10d=6.95

9.5-0.25d+0.10d=6.95

-015d=-2.55

d=-2.55/-0.15 = 17

q=38-17 =21

21*0.25 =5.25

17*0.10 = 1.70

5.25+1.70 = 6.95

she had 21 quarters and 17 dimes