After working for 8 days, Arun finds that only 13 rd of the work has been done. He employs Akhil who is 60% as efficient as Arun. How many days more would Akhil take to complete the work?

Arun has completed $\frac{1}{3}$rd of the work in 8 days

Then he can complete the total work in

$\frac{1}{3}$ ---- 8

 1 ---- ?

= 24 days

But given Akhil is only 60% as efficient as Arun

Akhil = $\frac{1}{24}\times \frac{60}{100}=\frac{1}{40}$

Akhil can complete the total work in 40 days

Now, remaining 2/3rd of work can be completed in

 1  ------   40

$\frac{2}{3}$ ------   ?  

= 26.66 days.