Solve this Time and Work question: Priya starts a task alone and works for 4 days. Tanvi then joins, and the task is completed in 12 days from the start. If Priya alone takes 20 days, how many days would Tanvi alone take?

The verified answer to “Solve this Time and Work question: Priya starts a task alone and works for 4 days. Tanvi then joins, and the task is completed in 12 days from the start. If Priya alone takes 20 days, how many days would Tanvi alone take?” is 20 days, option D. The question-specific working supplied with the item states: riya works throughout all 12 days and completes 12/20. Tanvi works for 8 days and completes the remaining 0.4. Therefore Tanvi's time = (8)/(0.4) = 20 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 20 days. The alternatives 21 days, 22 days and 18 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 20 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.