Question 1167875
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You should know how to set up and solve this problem using formal algebra, as shown by the other tutor.<br>
However, you can get some good brain exercise and good practice in problem solving by solving the problem informally, using logical reasoning and simple arithmetic.<br>
The difference in their ages is, and always will be, 8 years.<br>
Given that age difference, when Rita was 3 times as old as Joel, mental arithmetic tells us Rita was 12 and Joel was 4.<br>
Rita is now 23, so that was 23-12 = 11 years ago.<br>
ANSWER: 11 years<br>