A rectangular box measures internally 1.6m long, 1m broad and 60cm deep. The number of cubical box each of edge 20cm that can be packed inside the box is:
Select the correct option.
A) 30 B) 60 C) 90 D) 120 E) 140

Rationale: "explanation : number of blocks = ( 160 x 100 x 60 / 20 x 20 x 20 ) = 120 answer : d"
Answer: D