Average MCQ Set 8

AVERAGE MCQ SET 8

1. The average of 36 numbers was found to be 45 . Later , it was detected that 84 was misread as 48 . Find the correct average of the given numbers .

(a) 58

(b) 48

(c) 46

(d) 56

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Answer: C

2. The average of 45 numbers was found to be 39 . Later on , it was detected that a number 65 was misread as 56 . Find the correct average of the given numbers .

(a) 36.2

(b) 37.2

(c) 38.2

(d) 39.2

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Answer: D

3. The average of 16 numbers is 35 . It was found later that four numbers 18 , 17 , 24 and 35 were taken by mistake . What is the new average after removing these numbers ?

(a) 38.83

(b) 42.33

(c) 46.66

(d) 33.33

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Answer: A

4. The average of the marks of 25 students in a class , in an examination was calculated to be 19 . Later , the teacher realized that the marks of two students were taken as 18 and 19 respectively , instead of 14 and 15 . Find the new actual average marks of the class .

(a) 17.43

(b) 16.56

(c) 18.68

(d) 17.65

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Answer: C

5. A student finds the average of ten 2-digit numbers . while copying numbers by mistake , he writes one number with its digits interchanged . As a result his answer is 2.7 less than the correct answer . The difference of the digits of the number , in which he made mistake is :

(a) 3

(b) 5

(c) 4

(d) 2

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Answer: A

6. Average marks of 25 marks students is 40 . One student got 20 marks instead of 60 and other student got 90 marks in place of 80 . The number of student wrongly read as 25 instead 20 . Find the true average .

(a) 51.5

(b) 52

(c) 51

(d) 50

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Answer: A

7. In an examination , the average marks was found to be 50 . After deducing computational errors the marks of the 100 candidates had to be changed from 90 to 60 each and the average came down to 45 marks . The total number of candidates who took the exam , were :

(a) 300

(b) 600

(c) 200

(d) 150

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 Answer: B

8. Several students have taken an exam . There was as error in the answer key which affected the marks of 48 students , and their average marks reduced from 78 to 66 . The average of remaining students increased by 3.5 marks . This resulted the reduction of the average of all students by 4.5 marks . The number of students that attended the exam is :

(a) 96

(b) 84

(c) 93

(d) 100

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Answer: C

9. While finding the average marks of a class , Vikas marks were wrongly entered as 98 in place of 89 . Due to this error , the average marks of the class were 0.25 more than the actual average . What is the number of students in the class ?

(a) 32

(b) 38

(c) 34

(d) 36

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Answer: D

10. A student’s marks were wrongly entered as 65 instead of 45 . Due to this , the average marks for the class got increased by 1/3 . The number of students in the class is :

(a) 40

(b) 20

(c) 60

(d) 30

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Answer: C