Solve this Time and Work question: Rohit and Sameer can complete a project together in 10 days. Sameer and Imran can complete it in 12 days, while Imran and Rohit can complete it in 20 days. If Rohit works alone, how many days will he take to complete the project?

The verified answer to “Solve this Time and Work question: Rohit and Sameer can complete a project together in 10 days. Sameer and Imran can complete it in 12 days, while Imran and Rohit can complete it in 20 days. If Rohit works alone, how many days will he take to complete the project?” is 30 days, option D. The question-specific working supplied with the item states: Let the daily efficiencies of Rohit, Sameer and Imran be R, S and I. Then R + S = 1/10, S + I = 1/12, and I + R = 1/20. Add the first and third equations and subtract the second: 2R = 1/10 + 1/20 - 1/12. Rohit alone will complete the project in 30 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 30 days. The alternatives 36 days, 40 days and 24 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 30 days, so option D is uniquely correct. The method is transparent, question-specific and suitable for SSC, Railway, Banking, Defence, State and other competitive examinations.