We know that,
Number of hours A required to do a piece of work =24 hours
Number of B required to do a piece of work =16 hours
Let us consider number of hours C required to do a piece of work =x hours
Number of hours A,B and C together required to do piece of work =8 hours
∴ We can calculate, work done by A in 1 hour =124
Work done by B in 1 hour =116
Work done by C in 1 hour =1x
Work done by A,B and C together in a 1 hour =18
548+1x=18
(5x+48)48x=18
40x+384=48x
8x=384
∴C can do the work in 48 hours.