Asthn and Basu work together, they will complete a job in 7.5 days. However, if Astha works alone and completes half the job and then Basu takes over and completes the
remaining half alone, they will be able to complete the job in 20 days. How long will Basu alone take to do the job if Astha is as efficient than Basu?
O 10 day
20 day
0 30 day
40 day
Answers
Answer:
Given:
• A and B working together will complete a job in 7.5 days
• A works alone for few days and completes half the job
• After that, B takes over and completes the remaining half of the job, working alone
• Total time taken to complete the job = 20 days
• A is more efficient than B
To find:
• The time taken by B alone to complete the entire job
Approach and Working:
• A + B one day’s work =
Let us assume that A works for x days to complete half the job
• Implies, A’s one day work =
This implies, B takes 20 – x days to complete the remaining half of the work
• Implies, B’s one day work =
Thus,
• Implies,
Simplifying this, we get,
• x * (20 – x) = 5 * 15
Comparing the terms on both sides, we can infer that x = 5
• Thus, B’s one day work =
Therefore, B alone takes 30 days to complete the entire job
Hence, the correct answer is Option C