Question

The sum of three numbers is 20

the first is 4 times the sum of the other two
the second is seven times the third
what is the product of all three

Answer 1

A*B*C= 28

Explanation:

A+B+C=20

1. A = 4(B+C)

2. B = 7C

3. C = C

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1.

A = 4( 7C + C )

A=4(8C)

A= 32C

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A+B+C=20

32C + 7C + C = 20

40C = 20

C = 20/40

C = 1/2

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A= 32(1/2) = 32/2 = 16

B= 7(1/2) = 7/2

C= 1/2

A*B*C = 16 * 7/2 * 1/2

A*B*C= 28