Solution
Twice as Old as You Were
Show the problem again
Two people, me and you, have ages that sum to 63 years. I am now twice as old as you were at the time when I was as old as you are now. Both ages are whole numbers of years and I am the older one. How old am I? Give an integer.
Worked solution
Let my age be a and yours b. The time when I was b was a − b years ago, and your age then was b − (a − b) = 2b − a. The condition says a = 2(2b − a), so 3a = 4b, i.e. a : b = 4 : 3. With a + b = 63 this gives a = 36 and b = 27. Check: 9 years ago I was 27, you were 18, and 36 = 2 × 18. The answer is **36**.
Source: Classic age riddle in wide circulation; no traceable original source. Statement written for AxiomIQ.