Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: · Marks: · Difficulty:
The size of a wooden block is $5 \times 10 \times 20 \mathrm{cm}$. How many such blocks will be required to construct a solid wooden cube of minimum size?
(a)6
(b)8
(c)12
(d)16
Answer
Answer (as printed): B
Explanation
Side of smallest cube = L.C.M. of 5 cm, 10 cm, 20 cm $=20 \mathrm{cm}$. Volume of the cube $=(20 \times 20 \times 20) \mathrm{cm}^{3}=8000 \mathrm{cm}^{3}$. Volume of the block $=(5 \times 10 \times 20) \mathrm{cm}^{3}=1000 \mathrm{cm}^{3}$. $$\text { ∴ Number of blocks }=\left(\frac{8000}{1000}\right)=8 .$$