Work rate: A = 1/10, B = 1/15. Together = (1/10 + 1/15) = 5/30 = 1/6. So, 6 days.
कार्य दर: A = 1/10, B = 1/15। एक साथ = (1/10 + 1/15) = 5/30 = 1/6। अतः, 6 दिन।