9514 1404 393
Answer:
11 years ago
Step-by-step explanation:
When Z is 3 times as old as M, the ratio of their ages is ...
M : Z = 1 : 3
The difference in their ages at that time is 3 - 1 = 2 "ratio units". The difference in their current ages is 50 -24 = 26 years, so 1 ratio unit = 26/2 = 13 years. Z was 3 times as old as M when M was 13 years old. (Z was 39.)
That was 24 -13 = 11 years ago.
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For most age problems, the difference between two ages is assumed to be a constant.
