Surface Area and Volumes (IMO Mathematics Olympiad Class 9): Questions 72  77 of 104
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Question number: 72
» Surface Area and Volumes
Question
What change in percent is made in the area of a rectangle by decreasing its length and increasing its breadth by ?
Choices
Choice (4)  Response  

a. 


b. 


c. 


d. 


Question number: 73
» Surface Area and Volumes
Question
The heights of two cones are in the ratio of 3: 8 and their radius in the ratio 5: 3. Then the ratio of their volumes is ________
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Choice (4)  Response  

a. 


b. 


c. 


d. 


Question number: 74
» Surface Area and Volumes
Question
The area of rhombus is and one of its diagonals is 8 cm. its perimeter is ________
Choices
Choice (4)  Response  

a. 


b. 


c. 


d. 


Question number: 75
» Surface Area and Volumes
Question
The largest sphere is cut off from a cube of side 8 cm. the volume of the sphere will be ________
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Choice (4)  Response  

a. 


b. 


c. 


d. 


Question number: 76
» Surface Area and Volumes
Question
A spherical ball of lead, 9 cm in diameter is melted and recast into four spherical balls. The diameter of three of these are 3 cm, 2 cm, 2.5 cm is respectively. The radius of the fourth ball is________.
Choices
Choice (4)  Response  

a.  8.79 cm 

b.  6.79 cm 

c.  7.79cm 

d.  5.79 cm 

Question number: 77
» Surface Area and Volumes
Question
A cylindrical rod whose height is 12 times of its radius is melted and recast into spherical balls of same radius. The numbers of balls will be________
Choices
Choice (4)  Response  

a.  9 

b.  2 

c.  7 

d.  6 
