He has 20 quarters, 15 dimes and 10 pennies.
Step-by-step explanation:
Let,
Quarters = x
Dimes = y
Pennies = z
We know that,
A quarter is 25 cents, dime is 10 cents and penny is 1 cent.
Total amount = $6.60 = 6.60*100 = 660 cents
According to given statement;
25x+10y+z=660 Eqn 1
x=2z Eqn 2
y=z+5 Eqn 3
Putting these values of x and y in Eqn 1
Dividing both sides by 61;
Putting z=10 in Eqn 2
Putting z=10 in Eqn 3
He has 20 quarters, 15 dimes and 10 pennies.
Keywords: linear equations, substitution method
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