Sapna is double efficient as compared to Rakesh. If they both work together on a project and complete it in 48 days, then the number of days in which Sapna alone can complete the project is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 72.
Let the total work to be done be 144 units.
Also, let the efficiency of Rakesh be x units/day.
According to the given question,
Efficiency of Sapna = 2x units/day
Now, time taken by Sapna and Rakesh together to complete the project = 48 days
Total work = Efficiency × Time
⇒ = 48
⇒ 3x = 3
⇒ x = 1
So, time taken by sapna to complete the project alone =
⇒ = 72 days
Hence the number of days required by Sapna to complete the project is 72.