The ages of Old and Young total 48. Old is twice as old as Young was when Old was half as old as Young will be when Young is three times as old as Old was when Old was three times as old as Young.

How old is Old ?

(In reply to Solutions by DJ)

In
"When Old is three times as old as Young (call this time x):
Ax=3Bx=3(Ax-d)
Ax=3Ax-3d
Ax=(3/2)d "
what is the purpose of multiplying by x? (in fact, what is x to represent? ... years past the present?, years past one of their births?, etc.)

But in any case, the claim that Ax = 3Bx is really a claim that A=3B as the x's cancel. But that's claiming that Old is today three times as old as B. If x represents time past the present, it should be (A+x) = 3(B+x) = 3(A-d+x). And by the wording of the problem, I'm sure x would come out negative eventually to fit the tense.

Posted by Charlie on 2003-05-25 05:37:39