SOLUTION: a movie star unwilling to give his age posed the following riddle seven years ago i was eleven times as old as my daughter. now i am 4 times as old as she is. how old is the st

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: a movie star unwilling to give his age posed the following riddle seven years ago i was eleven times as old as my daughter. now i am 4 times as old as she is. how old is the st      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 562299: a movie star unwilling to give his age posed the following riddle
seven years ago i was eleven times as old as my daughter. now i am 4 times as old as she is. how old is the star?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +s+ = Star's age now
Let +d+ = Daughter's age now
+s+-+7+ = Star's age 7 yrs ago
+d+-+7+ = Daughter's age 7 yrs ago
--------------------------------
(1) +s+-+7+=+11%2A%28+d+-+7+%29+
(2) +s+=+4d+
-------------
(2) +d+=+s%2F4+
By substitution:
(1) +s+-+7+=+11%2A%28+s%2F4+-+7+%29+
(1) +s+-+7+=+%2811%2F4%29%2As+-+77+
(1) +4s+-+28+=+11s+-+308+
(1) +11s+-+4s+=+308+-+28+
(1) +7s+=+280+
(1) +s+=+40+
The star is 40
check:
(2) +d+=+s%2F4+
(2) +d+=+40%2F4+
(2) +d+=+10+
and
(1) +s+-+7+=+11%2A%28+d+-+7+%29+
(1) +40+-+7+=+11%2A%28+d+-+7+%29+
(1) +33+=+11d+-+77+
(1) +11d+=+77+%2B+33+
(1) +11d+=+110+
(1) +d+=+10+
OK