Answer:
21 years
Explanation:
Let x represent the number of years since Johann was 3 times Chad's age. The given relation can be written as the equation ...
(60 -x) = 3(34 -x)
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Solving this, we have ...
60 -x = 102 -3x . . . . . eliminate parentheses
2x = 42 . . . . . . . . . add 3x-60
x = 21 . . . . . . . . .divide by 2
21 years ago, Johann was 3 times as old as Chad.
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Additional comments
Their ages then were 39 and 13.
If you recognize the age difference is 60-34 = 26 years, and that J will be 3×C when C's age is half that difference, then you know C was 13 at that time. That was 34-13 = 21 years ago.