How many bricks each measuring 21cm x 10cm x 8cm, will be needed to build a wall 9m x 5m x 18.5m  Choose the correct option:  A) 4955  B) 4899  C) 4650  D) 7200  E) none of these

Rationale: "explanation : no . of bricks = volume of the wall / volume of 1 brick = ( 900 x 500 x 18.5 ) / ( 21 x 10 x 8 ) = 4955 answer : a"
Answer: A