A student need to practice maths problems. Its helps in developing problem solving skills. The problems shall not be (i) too simple, (ii) too difficult or (iii) too many. Simple problems are boring, difficult problems discourages (at times), and too many problems don't leave time for fun.

I selected following problems on volume and surface area for my son studying in class 8.

- A field is 80 m long and 50 m broad. In one corner of the field, a pit which is 10 m long, 7.5 m broad and 8 m deep has been dug out. The soil taken out of it is evenly spread over the remaining part of the field. Find the rise in the level of the field.
- Find the volume of wood used to make an open box whose external dimensions are 36 cm by 45 cm by 16.5 cm, the thickness of the wood being 1.5 cm thick throughout.
- Find the length of the longest pole that can be put inside the above box.
- How many soap of size 7 cm by 5.5 cm by 5 cm can be put into this box. Think!
- Find the breadth and the height of a cuboid with square base, being given the volume 63 $\mathrm{in}^3$ and surface area 102 $\mathrm{in}^2$.
- A rectangular piece of paper 22 cm by 6 cm is folded without overlapping to make a cylinder of height 6 cm. Find the curved surface area and volume of the cylinder.
- A rectangular vessel 22 cm by 16 cm by 14 cm is full of water. If the total water is poured into an empty cylindrical vessel of radius 8 cm, find the height of water in the cylindrical vessel.
- A well of inner diameter 14 m is dug to a depth of 12 m. The soil taken out of it has been evenly spread all around it to a width of 7 m to form an embankment. Find the height of the embankment so formed.
- A road roller takes 750 complete revolutions to move once over to level a road. Find the area of the road if the diameter of the road roller is 84 cm and its length is 1m.
- The length of a metallic tube is 1 m, its thickness is 1 cm and its inner diameter is 12 cm. Find the mass of the tube if the density of the metal is 7.7 grams per cubic centimeter.