Given: A's days to complete the work = 8 days B's days to complete the work = 12 days Concept Used: Total work is LCM of time taken by each person. Formula Used: Total work = Efficiency × Time Calculations: Let the efficiencies of A and B be a and b be respectively. Let the total work be completed in x days. Total work = LCM of (8, 12) = 24 Total work = Efficiency × Time ⇒ 24 = a × 8 ⇒ a = 24/8 = 3 Similarly, 24 = 12 × b ⇒ b = 24/12 = 2 They work together and A leaves 2 days before completion of the work ⇒ 3 × (x - 2) + 2 × x = 24 ⇒ 5x = 24 + 6 = 30 ⇒ x = 6 days ∴ The time in which total work is completed is 6 days. They work together and A leaves 2 days before completion of the work ⇒ 3 × (x - 2) + 2 × x = 24 ⇒ 5x = 24 + 6 = 30 ⇒ x = 6 days ∴ The time in which total work is completed is 6 days.