Question 955823: Two years ago, John was 3 times as old as Bob. In 5 years time, John will be twice as old as Bob. Find John's present age Found 2 solutions by stanbon, macston:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Two years ago, John was 3 times as old as Bob. In 5 years time, John will be twice as old as Bob. Find John's present age
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Equations:
j-2 = 3(b-2)
j+5 = 2(b+5)
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Simplify::
j-3b = -4
j-2b = 5
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Substiutute and solve for "b":
3b-4 = 2b+5
b = 9 (bob's age now)
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solve for "j":
j = 2b+5
j = 18+5 = 23 (john's age now)
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Cheers,
Stan H.
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You can put this solution on YOUR website! Two years ago, John was 3 times as old as Bob. In 5 years time, John will be twice as old as Bob. Find John's present age
J=John; B=Bob
J-2=3(B-2)
J-2=3B-6
J=3B-4
J+5=2(B+5) Substitute for J
3B-4+5=2B+10 Subtract 2B from each side.
B+1=10 Subtract 1 from each side.
B=9 ANSWER 1: Bob is 9 years old.
J=3B-4=3(9)-4=27-4=23 ANSWER 2: John is 23 years old.
CHECK:
J+5=2(B+5)
23+5=2(9+5)
28=2(14)
28=28
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