PreAlgebra
posted by Tania .
help me calculate this  my 6th grade nephew has this question for homework and I'm at a loss.
The combined age of 2 people is 91. Person A is two times as old as Person B was when Person A was as old as Person B is now.

My stab at it...
A+B=91 (Combined age)
A=2B
B=91A (Age of Person B now)
Substituting:
A=2(91A) = 60.66 or 60 2/3
60.66+B=91
B=30.33 (or 30 1/3)