How many planks each of which is `2m` long, `2. 5\ c m\ ` broad and `4c m\ ` thick can be cut-off from a wooden block `6m\ ` long, `15\ c m` broad and `40 c m` thick?

Explanation

Given
Dimensions of planks
Length` = 2m= 200`cm
Breadth` = 2.5`cm
Thick` = 4` cm
Dimensions of wooden block
Length` = 6m = 600`cm
Broad `= 15`cm
Thick ` =40`cm
Number of planks = volume of wooden block/volume of planks`=(600xx1540/2002.5xx4)`
`=12xx15`
`= 180`