A and B alone can do a work in 8 days and 12 days respectively. They together do a work for Rs. 1200 but A left the work in between and B completed the remaining work alone. If A received Rs. 120 less than his actual share then, for how many days did B worked alone to complete the work?
A and B alone can do a work in 8 days and 12 days respectively. They together do a work for Rs. 1200 but A left the work in between and B completed the remaining work alone. If A received Rs. 120 less than his actual share then, for how many days did B worked alone to complete the work? Correct Answer 2 days
⇒ A’s 1 day work = 1/8
⇒ B’s 1 day work = 1/12
Now,
⇒ Ratio of their shares = Ratio of their work efficiencies = (1/8) ∶ (1/12) = 12 ∶ 8 = 3 ∶ 2
⇒ A’s actual share = (3/5) × 1200 = Rs. 720
As, A left the work in between so A received Rs. 120 less than his actual share
⇒ A’s share = 720 - 120 = Rs. 600
⇒ B’s share = 1200 - 600 = Rs. 600
⇒ Ratio of their work done = Ratio of their shares = 600 ∶ 600 = 1 ∶ 1
Now,
⇒ Work done by A = Work done by B = 1/2
⇒ No. of days for which A worked = (1/2)/(1/8) = 4 days
⇒ No. of days for which B worked = (1/2)/(1/12) = 6 days
∴ B worked alone for = 6 - 4 = 2 days