5Dec19 SS Q30
- Option : B
- Explanation : Part of the tank filled in first hour by tap A and B = 1/8 + 1/10 = 9/40 tank Part of the tank filled in second hour by tap A and C = 1/8 + 1/12 = 5/24 Part of the tank filled in 2 hours 9/40 + 5/24 = 26/60 tank Part of the tank remains empty after 4 hours 1 - [8 x (26/60)] = 2/15 tank Time required to fill 2/15 tank by tap A and B 2/15 x 40/9 = 16/27 hour Hence, total time taken = 4 + (16/27) = 4(16/27)hours
