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Question

A bag of contains 30 coins. Some are dimes and some are quarters. The total amount of money in the bag is $3.45. How many dimes and how many quarters are in the bag?

Answer 1

d+q=30

10d+25q=345

10d+10q=10(30)=300

25q-10q= 15q=345-300= 45

15q=45

q= 45/15

q=3 quarters

d = 30-3 = 27 dimes

10(27)+25(3)

= 270+75

= 345