model 5 find new average from error Practice Questions Answers Test with Solutions & More Shortcuts
average PRACTICE TEST [9 - EXERCISES]
model 1 basic average questions
model 2 average of consecutive numbers
model 3 twice, thrice, one third etc. of numbers
model 4 find nth average from 1st & last number
model 5 find new average from error
model 6 find average of excluded number
model 7 average on ages/weight
model 8 find monthly income
model 9 average on cricket/exam
Question : 1 [SSC CGL Tier-II 2014]
The average of six numbers is 20. If one number is removed, the average becomes 15. What is the number removed ?
a) 35
b) 5
c) 45
d) 112
Answer »Answer: (c)
Required number = sum of six numbers – sum of five numbers
= 6 × 20 – 15 × 5
= 120 – 75 = 45
Question : 2 [SSC CHSL 2011]
A tabulator while calculating the average marks of 100 students of an examination, by mistake enters 68, instead of 86 and obtained the average as 58; the actual average marks of those students is
a) 57.82
b) 58.18
c) 57.28
d) 58.81
Answer »Answer: (b)
Difference = 86 – 68 = 18
∴ Actual average = 58 + $18/100$ = 58.18
Aliter : Using Rule 26,
The correct average will be = m +${\text"(a-b)"}/ \text"n"$.
Here, n = 100, m = 58
a = 86, b = 68
Correct Average = m + ${\text"(a - b)"}/\text"n"$
= 58 +${(86 -68)}/100$
= 58 + $18/100$
= 58 + 0.18 = 58.18
Question : 3 [SSC Multi-Tasking Staff 2013]
The average of l0 items was found to be 80 but while calculating, one of the items was counted as 60 instead of 50. Then the correct average would have been :
a) 79.25
b) 69
c) 79.5
d) 79
Answer »Answer: (d)
Corrected mean = ${80 × 10 – 60 + 50}/10$
= ${800 – 10}/10$ = $790/10$ = 79
Aliter : Using Rule 26,
The correct average will be = m +${\text"(a-b)"}/ \text"n"$.
Here, n = 10, m = 80
a = 50, b = 60
Correct Average = m + ${\text"(a - b)"}/\text"n"$
= 80+$ {(50- 60)}/10$
= 80 – 1 = 79
Question : 4
The mean of 20 items is 47. Later it is found that the item 62 is wrongly written as 26. Find the correct mean.
a) 47·7
b) 48·8
c) 46·6
d) 49·9
Answer »Answer: (b)
Difference = 62 – 26 = 36
∴ Required average = 47 +$36/20$ = 47 + 1.8 = 48.8
Aliter : Using Rule 26,
The correct average will be = m +${\text"(a-b)"}/ \text"n"$.
Here, n = 20, m = 47
a = 62, b = 26
Correct Average = m + ${\text"(a - b)"}/\text"n"$
= 47 + ${(62 – 26)}/20$
= 47+$36/20$
= 47 + 1.8 = 48.8
Question : 5
The average of 18 observations is recorded as 124. Later it was found that two observations with values 64 and 28 were entered wrongly as 46 and 82. Find the correct average of the 18 observations.
a) 122
b) 111$7/9$
c) 137$3/9$
d) 123
Answer »Answer: (a)
Difference in observations
= 64 + 28 – 46 – 82 = – 36
∴ Correct average = 124 -$36/18$ = 122
IMPORTANT quantitative aptitude EXERCISES
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Basic Average Questions Practice Test, Shortcuts, Tricks, PDF »
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New Average Aptitude MCQ Average of Consecutive Numbers »
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Top 99+ Average Aptitude: Twice, One Third of Numbers MCQ »
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New +99 Average Aptitude MCQ Find nth Average of Numbers »
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99+ Average Aptitude Find New Average from Error MCQ Test »
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Top 99+ Aptitude MCQ Test on Average With Excluded Number »
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Top 99+ Aptitude Average on Ages & Weights MCQ Test Quiz »
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Top Aptitude Average MCQ Find Monthly Income for Average »
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Top 149+ Aptitude Average on Cricket & Exam MCQ Test Quiz »
model 5 find new average from error Shortcuts »
Click to Read...model 5 find new average from error Online Quiz
Click to Start..average Shortcuts and Techniques with Examples
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model 1 basic average questions
Defination & Shortcuts … -
model 2 average of consecutive numbers
Defination & Shortcuts … -
model 3 twice, thrice, one third etc. of numbers
Defination & Shortcuts … -
model 4 find nth average from 1st & last number
Defination & Shortcuts … -
model 5 find new average from error
Defination & Shortcuts … -
model 6 find average of excluded number
Defination & Shortcuts … -
model 7 average on ages/weight
Defination & Shortcuts … -
model 8 find monthly income
Defination & Shortcuts … -
model 9 average on cricket/exam
Defination & Shortcuts …
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