Solve this Time and Work question: Farhan can finish a manuscript in 10 days. After Farhan works alone for 3 days, Kabir completes the remaining work. If Kabir alone needs 15 days for the whole manuscript, how many days does Kabir work?

The verified answer to “Solve this Time and Work question: Farhan can finish a manuscript in 10 days. After Farhan works alone for 3 days, Kabir completes the remaining work. If Kabir alone needs 15 days for the whole manuscript, how many days does Kabir work?” is 10.5 days, option B. The question-specific working supplied with the item states: arhan completes 3/10; remaining work = 1-3/10. At Kabir's rate 1/15, time = (1-3/10)×15 = 10.5 days. This working identifies the relevant work-rate equation and connects the given information to the required result. After applying the verified rule, the required value or position is 10.5 days. The alternatives 8.5 days, 11.5 days and 12.5 days fail because each breaks at least one stated condition, transition, direction or arithmetic step. A plausible-looking option is not sufficient unless it reproduces the complete work-rate equation. This full replay leads only to 10.5 days, so option B is uniquely correct. The method is transparent, question-specific and suitable for SSC, Railway, Banking, Defence, State and other competitive examinations.