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