FACTS  AND  FORMULAE  FOR  AVERAGE QUESTIONS

 

 

1. Average =Sum of observationsNo. of observations

2. Suppose a man covers a certain distance x kmph and an equal distance at y kmph. Then, the average speed during the whole journey is2xyx+yKmph

Q:

In a class of 78 students 41 are taking French, 22 are taking German. Of the students taking French or German, 9 are taking both courses. How many students are not enrolled in either course?

A) 6 B) 12
C) 24 D) 18
 
Answer & Explanation Answer: C) 24

Explanation:

You could solve this by drawing a Venn diagram. A simpler way is to realize that you can subtract the number of students taking both languages from the numbers taking French to find the number taking only French. Likewise find those taking only German. Then we have:Total = only French + only German + both + neither

78 = (41-9) + (22-9) + 9 + neither.

Not enrolled students = 24

Report Error

View Answer Report Error Discuss

Filed Under: Average
Exam Prep: GRE

20 22048
Q:

The average age of 15 students of a class is 15 years. Out of these, the average age of 5 students is 14 years and that of the other 9 students is 16 years, The age of the 15th student is :

A) 11 B) 12
C) 13 D) 14
 
Answer & Explanation Answer: A) 11

Explanation:

Age of the 15th student = [15 * 15 - (14 * 5 + 16 * 9)] = (225-214) = 11 years.

Report Error

View Answer Report Error Discuss

Filed Under: Average

20 21878
Q:

The average value of property of Mittal, Ambani and Singhania is Rs.11111 crore. The property of Singhania is as less than the property of Mittal is greater than the average property of both the Singhania and Mittal. The value of property of Ambani is :

A) Rs.111 crore B) Rs. 1111 crore
C) Rs. 11111 crore D) can't be determined
 
Answer & Explanation Answer: C) Rs. 11111 crore

Explanation:

M+A+S3=11111 

 

also S+M2=11111   ( M - 11111 = 11111 - S) 

 

=>A = 11111

Report Error

View Answer Report Error Discuss

Filed Under: Average

13 20077
Q:

Consider the following frequency distribution:

x     f

8     6

5     4

6     5

10    8

9     9

4     6

7     4

What is the median for the distribution?

A) 6 B) 7
C) 8 D) 9
 
Answer & Explanation Answer: C) 8

Explanation:
Summation of frequencies = 6+4+5+8+9+6+4 = 42
Median = mid value = average of 21st and 22nd value
Arranging data in increasing order we get

x     f

4     6

5     4

6     5

7     4

8     6

9     9

10    8

 
So mid value i.e 21st and 22nd value = 8
Report Error

View Answer Report Error Discuss

Filed Under: Average
Exam Prep: Bank Exams

0 19437
Q:

What will be the average of the first 7 positive odd numbers divisible by 5?

 

A) 45 B) 35
C) 40 D) 32
 
Answer & Explanation Answer: B) 35

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Average
Exam Prep: Bank Exams

0 19229
Q:

The average of five numbers is 27. If one number is excluded, the average becomes 25. The excluded number is :

A) 25 B) 35
C) 45 D) 55
 
Answer & Explanation Answer: B) 35

Explanation:

Excluded number = (27 x 5)  -  (25 x 4) = 135 - 100 = 35.

Report Error

View Answer Report Error Discuss

Filed Under: Average

31 19196
Q:

How many window coverings are necessary to span 50 windows, if each window covering is 15 windows long?

A) 4 B) 15
C) 3 D) 50
 
Answer & Explanation Answer: A) 4

Explanation:

Given that, 

Number of windows = 50

Each window covering covers 15 windows

=> 50 windows requires 50/15 window coverings

= 50/15 = 3.333

 

Hence, more than 3 window coverings are required. In the options 4 is more than 3. 

 

Hence, 4 window coverings are required to cover 50 windows of each covering covers 15 windows.

Report Error

View Answer Report Error Discuss

Filed Under: Average
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk , Bank PO , Database Administration , IT Trainer

13 19005
Q:

Average of 10 numbers is 14. If each number is multiplied by 6, then what will be the new average?

 

A) 70 B) 84
C) 56 D) 92
 
Answer & Explanation Answer: B) 84

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Average
Exam Prep: Bank Exams

1 18067