Q is as much younger than R, as he is older than T. If the sum of the ages of R and T is 50 years, what is the difference between R and Q's age?
Data inadequate
Let the ages of R, Q and T be r, q and t years respectively.
r - q = q - t
⟹r + t = 2q.
Also, r + t = 50
⟹q = 25 years
So, (r - q) cannot be determined.