A, B and C can do job in 9, 12 and 36 days respectively if they worked alone. A leaves after they have worked together for 3 days. In how many days can B and C do the rest of the job? A, B और C क्रमश: 9, 12 और 36 दिनों में एक कार्य अकेले कर सकते हैं। उन तीनो के एक साथ काम करने के 3 दिनों के के बाद A कार्य छोड़कर चला गया। B और C शेष कार्य एकसाथ कितने दिनों में कर सकते हैं?

The correct answer is C. First, calculate individual work rates: A can complete 1/9 of the work per day, B can complete 1/12 per day, and C can complete 1/36 per day. Together, their combined rate = 1/9 + 1/12 + 1/36 = 4/36 + 3/36 + 1/36 = 8/36 = 2/9 per day. In 3 days together, they complete 3 × (2/9) = 6/9 = 2/3 of the work. Remaining work = 1 - 2/3 = 1/3. After A leaves, B and C's combined rate = 1/12 + 1/36 = 3/36 + 1/36 = 4/36 = 1/9 per day. Time to finish remaining work = (1/3) ÷ (1/9) = 3 days.