A can complete a work in 18 days and B in 36 days. After working together for 5 days, what percentage of work remains? MCQ with Answer and Explanation

Explanation:
Combined rate = 1/20 + 1/15. Time = 1 ÷ combined rate = 8.57 days.

Explanation:
Completed percentage = (7/23)×100 = 30.43%.

Explanation:
Total work = LCM(8, 12, 6) = 24 units. Efficiency of (A+B) = 3, (B+C) = 2, (A+B+C) = 4. Efficiency of C = (A+B+C) - (A+B) = 4 - 3 = 1. Efficiency of A = (A+B+C) - (B+C) = 4 - 2 = 2. Combined efficiency of A and C = 2 + 1 = 3. Time taken by A and C together = 24 / 3 = 8 days.