A can do a piece of work in 5 days less than the time taken by B to do it. If both of them together take 111/9 days, then the time taken by B alone to do the same work (in days ) is ?

Answer: Option C

Try these question with the help of the option to save the time
Let B takes x days to complete the work
∴ A takes (x - 5)days

Now take the option 'B' i.e x = 20days
∴ Time taken by B = 20days and A = 15days
T.W = LCM of number of day taken by A and B = 60.
Work Efficiency ration A : B = 4 : 3
∴Total Time taken to complete the work together = $$\frac{60}{4+3}$$ =   $$8\frac{4}{7}$$  days
This option not matched with $$\text{11}\frac{1}{9}$$

Now take the option 'C' i.e x = 25days
∴ Time taken by B = 25days and A = 20days
T.W = LCM of number of day taken by A and B = 100.
Work Efficiency ration A : B = 5 : 4
∴Total Time taken to complete the work together = $$\frac{100}{5+4}$$ =   $$11\frac{1}{9}$$  days
Hence , Option (C) is the correct .