Question

A cube whose volume is $1/8$ cubic centimetre is placed on top of a cube whose volume is 1 $c{m}^3.$ The two cubes are then placed on top of a third cube whose volume is 8 $c{m}^3.$ The height of the stacked cubes is

• A. 3.5 cm
• B. 3 cm
• C. 7 cm
• D. None of these

Answer 1

The correct option is A

3.5 cm

$\text{Volume of first cube}=\frac{1}{8}c{m}^3$

$\therefore Edge=\sqrt[3]{3\frac{1}{8}}=\frac{1}{2}cm\text{Volume of second cube}=1c{m}^3\therefore Edge=\sqrt[3]{31}=1cm\text{Volume of third cube}=8c{m}^3\therefore Edge=\sqrt[3]{38}=\sqrt[3]{32^3}=2cm\text{Now height of the three cubes on placing one above the other}=\frac{1}{2}+1+2=3\frac{1}{2}cm=3.5cm$