Since Machine A does a job in 24 hours,

lets assume the number of units of work done to be a multiple of 24(for eg, 72 units)

So the rate of Machine A doing the work is

3 units/hourIt has been given that B does the work at \(\frac{2}{3}\)rd the rate of A.

Therefore Machine B does the work at the rate of

2 units/hourSince Machine A does the work for 8 hours,

Machine B does the rest of the work for

x days till the work is complete.

8*3 +

x*2 = 72(total units of work)

2

x = 48

x = 24

Therefore, Machine B takes 24 hours to complete the remaining work(Option C)

_________________

You've got what it takes, but it will take everything you've got