SOLUTION: Amy is now four times as old as Anna. Ten years from now she will be only twice as old Anna is then. How old are they now? Thank you

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: Amy is now four times as old as Anna. Ten years from now she will be only twice as old Anna is then. How old are they now? Thank you      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1099588: Amy is now four times as old as Anna. Ten years from now she will be only twice as old Anna is then. How old are they now? Thank you
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = Amy's age now
Let +b+ = Anna's age now
-------------------------------
(1) +a+=+4b+
(2) +a+%2B+10+=+2%2A%28+b+%2B+10+%29+
-------------------------------
Plug (1) into (2)
(2) +4b+%2B+10+=+2b+%2B+20+
(2) +2b+=+10+
(2) +b+=+5+
and
(1) +a+=+4b+
(1) +a+=+4%2A5+
(1) +a+=+20+
-----------------
Amy is 20
Anna is 5
-----------------
check:
(2) +a+%2B+10+=+2%2A%28+b+%2B+10+%29+
(2) +20+%2B+10+=+2%2A%28+5+%2B+10+%29+
(2) +30+=+2%2A15+
(2) +30+=+30+
OK