Question

The average age of seven boys sitting in a row facing North is 26 yr. If the average age of first three boys is 19 yr and the average age of last three boys is 32 yr, then what is the age of the boy who is sitting in middle of the row?

• A. 28 yr
• B. 29 yr
• C. 24 yr
• D. 31 yr
• E. None of these

Answer 1

The correct option is B 29 yr

Here, age of the fourth boy
= (26 $\times$ 7 - 3 $\times$ 19 - 3 $\times$ 32)yr
= (182 - 57 - 96)
= 29 yr