SOLUTION: three pieces of 25 cents and two pieces of a cent have a mass of 27 grams. two pieces of 25 cents pieces and six pieces of a cent have a mass of 32 grams. how is the mass of each p

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Question 139008: three pieces of 25 cents and two pieces of a cent have a mass of 27 grams. two pieces of 25 cents pieces and six pieces of a cent have a mass of 32 grams. how is the mass of each pieces
Answer by solver91311(24713) About Me  (Show Source):
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Let x be the mass of a quarter and y be the mass of a penny, so:

3x%2B2y=27
2x%2B6y=32

Multiply the first equation by -3:
-9x-6y=-81
2x%2B6y=32

Add the two equations term-by-term:
-7x%2B0y=-49
x=7

A quarter (25-cent piece) weighs 7 grams.

3%287%29%2B2y=27
21%2B2y=27
2y=6
y=3
A penny (1-cent piece) weighs 3 grams.

Those answers were made up to make the arithmetic come out neatly. A pre-1965 silver quarter weighs 6.25 grams. The copper-nickel quarters minted after 1964 weigh only 5.67 grams. Pennies vary in weight from 2.4 to 3.2 grams.