Let the boy take b days to complete the work
So,
\(\Rightarrow\;\)\(\frac{1}{6} + \frac{1}{8} + \frac{1}{b} = \frac{1}{3}\)
\(\Rightarrow\;\)\(\frac{1}{b} = \frac{1}{24}\)
\(\Rightarrow\;\)b = 24 days
Amount divided in inverse ratio of number of days taken, so
Days ratio = \(6:8:24\)
Inverse ratio of amount divison = \(\frac{1}{6}:\frac{1}{8}:\frac{1}{24} = 4:3:1\)
Boy's share = \(\frac{1}{8} \times 600 = Rs. 75\)
The correct option is (A): Rs 75