Abhinav is 2 times as good a workman as Balwant and therefore is able to finish a job in 36 days less than Balwant. Working together, they can do it in

Ratio of times taken by Abhinav and Balwant = 1 : 2

The time difference is (2 - 1) 1 day while Balwant take 2 days and Abhinav takes 1 day.

If difference of time is 1 day, Balwant takes 2 days.

If difference of time is 36 days, Balwant takes = $$\frac{2}{1} \times 36 = 72$$ days

So, Abhinav takes 36 days

Akbhinav's 1 day's work = $$\frac{1}{36}$$

Balwant's 1 day's work = $$\frac{1}{72}$$

(Abhinav + Balwant)'s 1 day's work together = $$\frac{1}{36} + \frac{1}{72} = \frac{3}{72} = \frac{1}{24}$$

$$\therefore$$ Abhinav and Balwant together can do the work in = 24 days

=> Ans - (D)