Exams › SSC CGL (Prelims) › General
The average age of 10 students in a class increases by 1 year when a 30-year-old teacher joins them. What was the original average age of the students?
- 18
- 19
- 20
- 21
Correct answer: 19
Solution
If the average of 10 students increases by 1 year, the total age of the group of 10 students increases by 10 when the teacher is included in the new average setup. Let the original average be $x$; then the new average becomes $x+1$. Using the teacher's age of 30, the original average works out to 19 years.
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