Exams › SSC CGL (Prelims) › General

Three batches of students have average ages 17, 19, and 23 years respectively. If their numbers are in the ratio 3:4:6, what is the overall average age of all the students?

1. 19.41
2. 20.38
3. 21.20
4. 18.9

Correct answer: 20.38

Solution

The overall average is the weighted average of the three batch averages. Using weights 3, 4, and 6 gives (173 + 194 + 236)/(3+4+6). This equals 265/13 20.38.

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