SOLUTION: Joe is twice as old as David. The sum of their ages is 63. How old are David and Joe

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Question 832899: Joe is twice as old as David. The sum of their ages is 63. How old are David and Joe
Found 2 solutions by stanbon, JulietG:
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
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Joe is twice as old as David.
The sum of their ages is 63.
How old are David and Joe
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Equations:
j = 2d
j+d = 63
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Substitute for "j" and solve for "d":
2d + d = 63
3d = 63
David = 21 years
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Solve for "j":
j = 2d
Joe = 2*21 = 42 years
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Cheers,
Stan H.
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Answer by JulietG(1812)   (Show Source): You can put this solution on YOUR website!
J = 2D
J + D = 63
To solve this, substitute the value of J into the second equation.
J + D = 63
(2D) + D = 63
3D = 63
Divide each side by 3
D = 21
.
If David is 21, then Joe is 42 -- twice as old

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