A and C together can complete a certain work in 30 days. B is 20% more efficient than C. A, B and C together can do the same work in 20 days. C alone completed one fourth of the work and the remaining work was completed by A and B together. In how many days was the entire work completed?
A and C together can complete a certain work in 30 days. B is 20% more efficient than C. A, B and C together can do the same work in 20 days. C alone completed one fourth of the work and the remaining work was completed by A and B together. In how many days was the entire work completed?
Solution
Let the total work be units (LCM of and for clean calculations).
Find the work rates:
complete units in days, so units/day
complete units in days, so units/day
Therefore, unit/day
Since is more efficient than :
units/day
units/day
Phase 1: completes of the work
Work done by units
Time taken by days
Phase 2: and complete remaining work
Remaining work units
Combined rate of and units/day
Time taken by and days
Total time days