A and B together work for 3 days, B then worked alone for 2 days, A then worked alone for 3 days and the work was finished. If A works for 8 days alone and B works for 4 days alone, the work will be finished. How many days will A alone work if B works for 5 days alone?
A and B together work for 3 days, B then worked alone for 2 days, A then worked alone for 3 days and the work was finished. If A works for 8 days alone and B works for 4 days alone, the work will be finished. How many days will A alone work if B works for 5 days alone? Correct Answer 6
Given:
A and B together work for 3 days, B then worked alone for 2 days, A then worked alone for 3 days and the work was finished.
If A works for 8 days alone and B works for 4 days alone, the work will be finished.
Calculation:
Let the work done by A, B and C in a day be A, B and C respectively.
Given, 3(A + B) + 2B + 3A = 1
Or, 6A + 5B = 1
Also, 8A + 4B = 1
Equating the two equations, we get,
⇒ 6A + 5B = 8A + 4B
Or, B = 2A
Capacity B / A = 2 / 1
So, Total work = 6A + 5B = 6 × (1) + 5 × (2) = 16 units
Let A alone work for N days
⇒ N × A + 5B = 16
⇒ N × (1) + 5 × (2) = 16
⇒ N = 6 days