volume and surface area
2.  In a shower, 5 cm of rain falls. The volume of water that falls on 1.5 hectares of ground is:  
Answer: Option B Explanation:
1 hectare = 10,000 m^{2} So, Area = (1.5 x 10000) m^{2} = 15000 m^{2}.

3.  A hall is 15 m long and 12 m broad. If the sum of the areas of the floor and the ceiling is equal to the sum of the areas of four walls, the volume of the hall is:  
Answer: Option C Explanation:
2(15 + 12) x h = 2(15 x 12)

4.  66 cubic centimetres of silver is drawn into a wire 1 mm in diameter. The length of the wire in metres will be:  
Answer: Option A Explanation:
Let the length of the wire be h.

5.  A hollow iron pipe is 21 cm long and its external diameter is 8 cm. If the thickness of the pipe is 1 cm and iron weighs 8 g/cm^{3}, then the weight of the pipe is:  
Answer: Option B Explanation:
External radius = 4 cm, Internal radius = 3 cm.
Weight of iron = (462 x 8) gm = 3696 gm = 3.696 kg. 