Rohit, Mohit and Sumit individualy can complete a work in 8 days, 14 days and 21 days respectively. In how many days these three together can complete the same work?

Let total work to be done be L.C.M.(8,14,21) = 168 units

Rohit complete it in 8 days, => Rohit's efficiency = $$\frac{168}{8}=21$$ units/day

Similarly, Mohit's efficiency = $$\frac{168}{14}=12$$ units/day

And Sumit's efficiency = $$\frac{168}{21}=8$$ units/day

Thus, total work done in 1 day = $$(21+12+8)=41$$ units

$$\therefore$$ Time taken to complete the work when all are working together = $$\frac{168}{41}$$ days

=> Ans - (B)