X can do a piece of work in 40 days. He works at it for 8 days and then Y finishes it in 16 days. How long will they together take to complete the work?
The correct option is A: 403 days
Work done by X in 8 days = (140 × 8) = 15
Remaining work = (1 − 15) = 45
Now, 45 work is done by Y in 16 days
Whole work will be done by Y in (16 × 54) = 20 days
∴ X's 1 day's work = 140, Y's 1 day's work = 120,
(X + Y)'s 1 day's work = (140 + 120) = 340
Hence, X and Y will together complete the work in 403 = 1313 days