O P Malhotra, S K Gupta and, Anubhuti Gangal Solutions for Chapter: Volume and Surface Area of Solids, Exercise 2: Mental Maths

If the volume of a cuboid whose dimensions are $18 \mathrm{cm}\times 10 \mathrm{cm}\times 8 \mathrm{cm}$ is $V {\mathrm{cm}}^3$ then find $V$.

If the volume of cube of edge $6 \mathrm{cm}$ is $V {\mathrm{cm}}^3$ then find $V$.

If the surface area of cube of side $8 \mathrm{cm}$ is $k {\mathrm{cm}}^2$, then find the value of $k$.

If the volume of a cube is $729 {\mathrm{cm}}^3$,find its surface area (excluding units).

A rectangular oil tank is $5 \mathrm{m}$ high, $3 \mathrm{m}$ long and $2 \mathrm{m}$ wide.How many litres of oil can it hold?  $\left[Given 1{\mathrm{m}}^3=1000 \mathrm{litres}\right]$