Work

INTRODUCTION:
The questions are based on the following factors.
The number of days taken by different persons
The efficiencies of different persons.
The work schedule.

SOME IMPORTANT POINTS:
(i) Number of days α 1/Efficiency
(ii) Ratio between efficiency α 1/ Ratio of number of days.

METHOD :
Take the L.C.M of the number of days taken by different persons and consider it as the total part of the work. By taking the L.C.M as the total part of the work, find out ,in 1 day they can do how many parts. Then find out, the given work will be completed in how many number of days