Two workers ‘A’ and ‘B’ working together completed a job in 5 days. Had ‘A’ worked twice as efficiently as he actually did and ‘B’ worked one-third as efficiently as he actually did, the work would have completed in 3 days. In how many days could ‘A’ alone complete the job?
Two workers ‘A’ and ‘B’ working together completed a job in 5 days. Had ‘A’ worked twice as efficiently as he actually did and ‘B’ worked one-third as efficiently as he actually did, the work would have completed in 3 days. In how many days could ‘A’ alone complete the job? Correct Answer <span class="math-tex">\(6\frac{1}{4}\:days\)</span>
Let A can alone complete the work in ‘x’ days.
⇒ A’s 1-day work = 1/x
∵ A and B together completed the work in 5 days.
⇒ B’s 1-day work = 1/5 - 1/x
Now, if A worked twice & B worked 1/3rd in a day, time taken = 3 days
⇒ 2(1/x) + (1/3)(1/5 - 1/x) = 1/3
⇒ 2/x + 1/15 - 1/3x = 1/3
⇒ 5/3x = 4/15
⇒ x = 5/3 × 15/4 = 25/4 days
∴ A can alone complete the work in 25/4 days
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Feb 20, 2025