A can complete a certain piece of work in 40 days. B is 25% more efficient than A and C is 28% more efficient than B. They work together for 5 days. The remaining work will be completed by B alone, in:

$16\frac{3}{5}$ days

Let Efficiency of A = 4

Efficiency of B = 100 x \(\frac{5}{4}\) = 5

Efficiency of C = 5 x \(\frac{32}{25}\) = \(\frac{32}{5}\)

Efficiency ratio of A, B, C = 4 : 5 : \(\frac{32}{5}\) = 20 : 25 : 32

Total work = 20 x 40 = 800

Work done by A , B , C in 5 days = (20 + 25 + 32) x 5 =385

Remaining work = 800 - 385 = 415

Therefore, Remaining work completed in = \(\frac{415}{25}\) = \( { 16}_{ 5}^{ 3} \) days.