Concept:\(efficiency = \frac {work}{total~ time~ taken}\)work done = efficiency × time takenCalculation:Given:A alone takes 6 days and B alone takes 8 days to complete the work, A, B and C together completed work in 3 days.amount given for work = Rs. 3200work done by C = total work - (Work done by A + work done by B)Work done by C = \(w -(3\times \frac w6 + 3\times \frac w8)= w-\frac {7}{8}w = \frac w8\)Amount paid to C = \(\frac {work ~done ~by ~C}{Total ~work}\times Cost ~of ~work= \frac {\frac w8}{w}\times 3200=\frac 18\times 3200=400\)Hence, Rs. 400 is to be paid to C