Correct Option: B

Let us consider Efficiency of men = p
And Efficiency of boys = q
2 men and 7 boys can complete a work in 14 days .
Total amount of work = Efficiency × No of days required to complete the work
⇒ (2p + 7q) × 14 ……………….(1)
3 men and 8 boys can complete the same work in 11 days.
Total Work = (3p+8q) × 11 ………………..(2)
From equations ( 1 ) & ( 2 ) ,we get
(2p + 7q) × 14 = (3p + 8q) × 11
⇒ 28p + 98q = 33p + 88q
⇒ 10q = 5p
⇒ p = 2q …………….(3)
Which mean the efficiency of men is double of the boys.
Now, Total Work = (2p + 7q) × 14
⇒ (4q + 7q) × 14 = 154q
Total work = 154q or 77p
8 men and 6 boys take to complete 3 times of that work .
Total Efficiency = 8p + 6q = 22q or 11p
Total Work = 3 × (154q) = 462q or, 3 × 77p = 231p