Mental Ability Test Surface area and Volume T2

A cube with a 5 cm edge is cut into cubes with a 2 cm edge. The ratio of the total surface of smaller cube to the total surface of the larger cube will be:

• (A) 1:25

• (B) 2:5 

• (C) 64:625

• (D) 4:25

A metal parallelopiped of measures 16 cm X 11 cm X 10 cm was melted to make coins. 

How many coins were made if the thickness and diameter of each coin was 2 mm & 2 cm resp.

• (A) 2800

• (B) 2500

• (C) 1800

• (D) 1500

A cylindrical wrapper of flat toffy is shown. The radius of a toffy is 7 mm and its thickness is 5 mm. How many such tablets are wrapped in the wrapper of height 10 cm and diameter 14 mm?

• (A) 28

• (B) 25

• (C) 20

• (D) 15

The curved surface area and the slant height of a right circular cone are 858 sq. cm and 13 cm respectively. Find its diameter (in cm)

• (A) 21

• (B) 42

• (C) 84

• (D) 63

A solid sphere of diameter 17.5 cm is cut into two equal halves. What will be the increase (in sq. cm) in total surface area ?

• (A) 289

• (B) 361.5

• (C) 481.05

• (D) 962.5

Radius of hemisphere is thrice than that of a sphere. What is the ratio of total surface area of hemisphere to that of sphere ?

• (A) 27:8

• (B) 21:4  

• (C) 27:4  

• (D) 6:1

A solid cone of height 24 cm and radius of its base 8 cm is melted to form a solid cylinder of radius 6 cm and height 6 cm. In the whole process what percent of material is wasted?

• (A) 48.5

• (B) 37.5  

• (C) 57.8  

• (D) 64

A hollow garden roller, 63 cm wide and outer radius 70 cm, is made of 4 cm thick iron. Find the volume of the iron.

• (A) 107712

• (B) 110225  

• (C) 201188  

• (D) 220211

Three spherical balls of radius 3 cm, 2 cm and 1 cm are melted to form a new spherical ball. In this process there is a loss of 25% of the material. What is the radius (in cm) of the new ball ?

• (A) 5

•   (B) 3

• (C) 6

• (D) 8

A cylindrical well of height 20 metres and radius 14 metres is dug in a field 72 metres long and 44 metres wide. The earth taken out is spread evenly on the field. What is the increase(in metre) in the level of the field.

• (A) 6.67

• (B) 3.56

• (C) 5.61

• (D) 4.83