Answer:
Option B
Explanation:
3 men = 6 boys = (6 men + 2 boys) = 14 boys.
More work, More days (Direct Proportion)
More boys, Less days (Indirect Proportion)
More hours per day, Less days (Indirect Proportion)
$\left\{\begin{array}{c}Work\quad\quad\quad\quad\quad\quad 1:2\\ Boys\quad\quad\quad\quad\quad\quad 14:6\\Hours/Day\quad\quad\quad\quad 8:7\end{array}\right\}::10:x$
$\therefore (1\times 14\times 8\times x)$ $=(2\times 6\times 7\times 10)$
$\Leftrightarrow x=\frac{840}{112}$ $=7\frac{1}{2}$
