SOLUTION: Ten years ago A was half of B's Age. If ratio of their present ages is 3:4 then what is the total of their persent ages?

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: Ten years ago A was half of B's Age. If ratio of their present ages is 3:4 then what is the total of their persent ages?       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 484383: Ten years ago A was half of B's Age. If ratio of their present ages is 3:4 then what is the total of their persent ages?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Ten years ago A was half of B's Age.
a - 10 = .5(b-10)
a - 10 = .5b - 5
a = .5b - 5 + 10
a = .5b + 5
:
If ratio of their present ages is 3:4 then what is the total of their present ages?
a%2Fb = 3%2F4
4a = 3b
Replace a with (.5b+5) from the 1st statement
4(.5b + 5) = 3b
2b + 20 = 3b
20 = 3b - 2b
b = 20 yrs is B's present age
then
a = .5(20) + 5
a = 15 yrs is A's present age
and
20 + 15 = 35 yrs is the total of their present ages