<PRE><B>Question 979835</B>
Hi there,
Bob was thrice as old as john 5 years ago
B - 5 = 3(J - 5)......(1)
Now he is only twice as old as john
B = 2J.......(2)
Multiplying out equation (1)
B - 5 = 3J - 15
Substituting 2J for B from (2)
2J - 5 = 3J - 15
Collect like terms
2J - 3J = - 15 + 5
-J = - 10
J = 10
Bob is 20yrs old
Jim is 10yrs old now.
Hope this helps:-)</PRE>