SOLUTION: Bob is half as old as Tom. One year ago Bob age was two fifths of what Tom's age will be a year from now. Can you figure out Bob's age and Tom's age.

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: Bob is half as old as Tom. One year ago Bob age was two fifths of what Tom's age will be a year from now. Can you figure out Bob's age and Tom's age.      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 149108: Bob is half as old as Tom.
One year ago Bob age was two fifths of what Tom's age will be a year from now.
Can you figure out Bob's age and Tom's age.

Found 2 solutions by ankor@dixie-net.com, josmiceli:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Write an equation for each statement:
:
"Bob is half as old as Tom."
B = 1%2F2T
or
T = 2B
:
"One year ago Bob age was two fifths of what Tom's age will be a year from now."
B - 1 = 2%2F5(T + 1)
Multiply equation by 5 to get rid of the denominator, results:
5(B - 1) = 2(T + 1)
:
5B - 5 = 2T + 2
:
5B = 2T + 2 + 5
:
5B = 2T + 7
:
Can you figure out Bob's age and Tom's age.
:
Substitute 2B for T in the above equation
5B = 2(2B) + 7
5B = 4B + 7
5B - 4B = 7
B = 7 yrs is Bob's age
Then
T = 2(7)
T = 14 yrs is Tom's age
:
:
Check solution using the statement:
"One year ago Bob age was two fifths of what Tom's age will be a year from now."
7 - 1 = 2%2F5(14 + 1)
6 = 2%2F5*15

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let B = Bob's age now
Let T = Tom's age now
B+=+%281%2F2%29%2AT
B+-+1 = Bob's age 1 year ago
T+%2B+1 = Tom's age 1 year from now
B+-+1+=+%282%2F5%29%2A%28T+%2B+1%29
5%2A%28B+-+1%29+=+2%2A%28T+%2B+1%29
5B+-+5+=+2T+%2B+2
5B+=+2T+%2B+7
Since
B+=+%281%2F2%29%2AT
%285%2F2%29%2AT+=+2T+%2B+7
5T+=+4T+%2B+14
T+=+14
B+=+%281%2F2%29%2A14
B+=+7
Bob's age is 7 and Tom's age is 14
check:
B+-+1+=+%282%2F5%29%2A%28T+%2B+1%29
7+-+1+=+%282%2F5%29%2A%2814+%2B+1%29
6+=+%282%2F5%29%2A15
30+=+30
OK