Average [NRA CGL (National Recruitment AgencyCombined Graduate Level) Mathematics]: Questions 15  19 of 25
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Question 15
Question
MCQ▾In a school with 900 students, the average age of boys is 12 years and that of the girls is 11 years and 6 months. If the average age of the school is 11 years and 9 months, then the number of the girls in the school is
Choices
Choice (4)  Response  

a.  390  
b.  450  
c.  760  
d.  460 
Question 16
Question
MCQ▾The average marks of 30 students in a test is 60. Later it is found that three marks 55,65& 50 were wrongly entered as 53,68 & 59. The average marks after mistakes were rectified is
Choices
Choice (4)  Response  

a.  95.67  
b.  59.67  
c. 
 
d. 

Question 17
Question
MCQ▾The average age of 40 students of a class is 10 years. When 20 new students are admitted, the average age is increased by 0.5 years. The average age of new students is (Paper I)
Choices
Choice (4)  Response  

a.  11.3 years  
b.  11.2 years  
c.  11.4 years  
d.  11.5 years 
Question 18
Question
MCQ▾The average weight of 8 persons decreases by 5 kg when one of them weighing 120 kg is replaced by a new person. The weight (in kg) of the new person is (Paper I)
Choices
Choice (4)  Response  

a.  68  
b.  80  
c.  74  
d.  77 
Question 19
Question
MCQ▾The average weekly salary of A, B and C is Rs. 5000 and that of B, C and D is Rs. 6000. If the weekly salary of A is Rs. 3000 then the weekly salary of D is (Paper  I)
Choices
Choice (4)  Response  

a.  Rs. 6300  
b.  Rs. 6000  
c.  Rs. 6054  
d.  Rs. 6050 