Question 955219: Paula has 30 coins in dimes and quarters. Their total value is $4.50 How many coins of each type does she have? Answer by macston(5194) (Show Source):
You can put this solution on YOUR website! D=dimes; Q=quarters
D+Q=30
D=30-Q
$0.10D+$0.25Q=$4.50 Substitute for D
$0.10(30-Q)+$0.25Q=$4.50
$3.00-$0.10Q+$0.25Q=$4.50 Subtract $3.00 from each side.
$0.15Q=$1.50 Divide each side by $0.15
Q=10 ANSWER 1: There are 10 quarters.
D=30-Q=30-10=20 ANSWER 2: There are 20 dimes.
CHECK:
$0.10D+$0.25Q=$4.50
$0.10(20)+$0.25(10)=$4.50
$2.00+$2.50=$4.50
$4.50=$4.50
