Ruchi, Khushi and Teju can do a piece of work in 30, 40 and 60 days respectively. In how many days can Ruchi do the work, if she is assisted by both Khushi and Teju on every third day?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. days
Calculations:
Total work (LCM of 30, 40 and 60) = 240 units
Efficiency of Ruchi = 240/30 = 8 units
Efficiency of khushi = 240/40 = 6 units
Efficiency of teju = 240/60 = 4 units
Total efficiency = 18 units
Work done in 3 days = 8 + 8 + 18 = 34 units
Work done in 21 days = 238 units
Now the 2 unit work will be done = 2/8 days
Total time taken = 21 + 1/4 = 85/4 days