The ratio of efficiencies of A, B and C is 2 : 5 : 3. Working together they can finish the work in 16 days. How much time will it take for B and C to complete the same work?

20 days

Total work = efficiency x number of days 

                = 10 x 16 = 160      

Time taken by B and C to complete the same work = \(\frac{Total\; work}{Efficiency}\) 

                                                                          = \(\frac{160}{8}\) = 20 days