Wages are paid in the proportion of work done.

SOLUTION: Let total work be 360units(LCM 40,60,12)

Thus efficiencies of A,B,C are 360/90,360/40,12=4,9,30 units respectively or43 units together in a day(4+9+30)

Total work in 24 days=43*8=344 units[Every 3 days 43 units of work is done and 344 is the nearest number to 360 as a multiple of43]

In the next two days(25th and 26th) 4+9=13 units of work is completed by A and B respectively.
By now 344+13=357 units of work has been done

Remaining work =360-357=3 units

This at the rate of 30units a day is completed by C in 3/30=1/10th of the 27th day.

Hence A&B worked for 9 days each and completed 9*4=36 and 9*9=81units of work respectively.

Total work A & B completed is 36+81=117units.

Rest of the work(360-117)=243 units is done by C alone.

Wages shall also be distributed in the ratio of work done which is 36,81,243 (B)