Mandar works 3 times as fast as Samarth. If Samarth can complete a job alone in 28 days, then in how many days can they together finish the job?
- A4 days
- B5 days
- C8 days
- D7 days
Solution & Step-by-step Explanation
Let the efficiency of Samarth be 1 unit/day.
Since Mandar works 3 times as fast as Samarth, Mandar's efficiency is 3 units/day.
Total work can be calculated from Samarth's performance:
Total Work=Efficiency of Samarth×Days taken by Samarth
Total Work=1 unit/day×28 days=28 units
Combined efficiency of Mandar and Samarth together:
Total Efficiency=3+1=4 units/day
Number of days required to complete the job together:
Days=
Total Efficiency
Total Work
=
4
28
=7 days
Since Mandar works 3 times as fast as Samarth, Mandar's efficiency is 3 units/day.
Total work can be calculated from Samarth's performance:
Total Work=Efficiency of Samarth×Days taken by Samarth
Total Work=1 unit/day×28 days=28 units
Combined efficiency of Mandar and Samarth together:
Total Efficiency=3+1=4 units/day
Number of days required to complete the job together:
Days=
Total Efficiency
Total Work
=
4
28
=7 days