11. 

A large cube is formed from the material obtained by melting three smaller cubes of 3, 4 and 5 cm side. What is the ratio of the total surface areas of the smaller cubes and the large cube?

A. 2 : 1
B. 3: 2
C. 25: 18
D. 27: 20

12. 

How many bricks, each measuring 25 cm x 11.25 cm x 6 cm, will be needed to build a wall of 8 m x 6 m x 22.5 cm?

A. 5600
B. 6000
C. 6400
D. 7200

13. 

What is the total surface area of a right circular cone of height 14 cm and base radius 7 cm?

A. 344.35 cm2
B. 462 सेमी 2
C. 498.35 सेमी 2
D. इनमे से कोई नहीं

14. 

A cistern of capacity 8000 litres measures externally 3.3 m by 2.6 m by 1.1 m and its walls are 5 cm thick. The thickness of the bottom is:

A. 90 cm
B. 1 डेसीमीटर
C. 1 मीटर
D. 1.1 सेमी

15. 

The curved surface area of a cylindrical pillar is 264 m2 and its volume is 924 m3. Find the ratio of its diameter to its height.

A. 3 : 7
B. 7: 3
C. 6: 7
D. 7: 6