A and B can make a wall in 48 min and 108 min respectively. C can distroy it at 5 bricks/minutes. When all the three are working together, they make the wall in 54 minutes. The number of bricks in the wall is?

432

Efficiency : A + B - C = 8 b/m

⇒ 9+ 4 - C = 8

⇒ C = 5        (given C = 5 liter/minutes)

Therefore, Total number of bricks = 432 liters