The average age of 9 girls is 16 years. The average age of 11 boys is 26 years. What is the average age of all these boys and girls taken together?
Answer & explanation
Correct answer: option 4
Sum of age of 9 girls = 9 × 16 = 144 years
Sum of age of 11 boys is = 11 × 26 = 286 years
Average of all boys and girls together = \(\frac{144 + 286 }{20}\)
= \(\frac{430}{20}\) = 21.5 years