Question:A rectangular block `6` cm by `12` cm by `15` cm is cut up into exact number of equal cubes. The least possible number of cubes will be :
A `6`
B `11`
C `33`
D `40`
/113
+ Answer
D
+ ExplanationVolume of block
`= (6 xx 12 xx 15) cu. cm`
`= 1080 cu. cm`.
The side of largest cube
= H.C.F.of `6 cm, 12 cm, 15 cm = 3 cm`.
Volume of this cube
`= (3 xx 3 xx 3) cm^3 = 27 cm^3`
Number of cubes
`= (1080/27)`
`= 40`.