model 4 find nth average from 1st & last number Section-Wise Topic Notes With Detailed Explanation And Example Questions
MOST IMPORTANT quantitative aptitude - 9 EXERCISES
-
Basic Average Questions Practice Test, Shortcuts, Tricks, PDF »
-
New Average Aptitude MCQ Average of Consecutive Numbers »
-
Top 99+ Average Aptitude: Twice, One Third of Numbers MCQ »
-
New +99 Average Aptitude MCQ Find nth Average of Numbers »
-
99+ Average Aptitude Find New Average from Error MCQ Test »
-
Top 99+ Aptitude MCQ Test on Average With Excluded Number »
-
Top 99+ Aptitude Average on Ages & Weights MCQ Test Quiz »
-
Top Aptitude Average MCQ Find Monthly Income for Average »
-
Top 149+ Aptitude Average on Cricket & Exam MCQ Test Quiz »
The following question based on average topic of quantitative aptitude
(a) 4
(b) 11
(c) 7
(d) 3
The correct answers to the above question in:
Answer: (b)
Using Rule 1,
Average of two or more numbers/quantities is called the mean of these numbers, which is given by
$\text"Average(A)" = \text"Sumof observation / quantities"/\text"No of observation / quantities"$
∴ S = A × n
Fourth number
= (4×4+4×4 – 3×7)
= (16 +16-21) = 11
Discuss Form
Read more find nth term Based Quantitative Aptitude Questions and Answers
Question : 1
Out of four numbers, the average of the first three is 18 and that of the last three is 16. If the last number is 19, the first is
a) 18
b) 25
c) 20
d) 19
Answer »Answer: (b)
Using Rule 1,
Average of two or more numbers/quantities is called the mean of these numbers, which is given by
$\text"Average(A)" = \text"Sumof observation / quantities"/\text"No of observation / quantities"$
∴ S = A × n
a + b + c = 18 × 3 = 54
and, b + c + d = 16 × 3 = 48
∴ a + b + c – b – c – d
⇒ 54 – 48 = 6
⇒ a – d = 6
⇒ a – 19 = 6
⇒ a = 19 + 6 = 25
Question : 2
The average of 30 numbers is 12. The average of the first 20 of them is 11 and that of the next 9 is 10. The last number is
a) 45
b) 50
c) 40
d) 60
Answer »Answer: (b)
Using Rule 1,
Average of two or more numbers/quantities is called the mean of these numbers, which is given by
$\text"Average(A)" = \text"Sumof observation / quantities"/\text"No of observation / quantities"$
∴ S = A × n
Last number
= 30 × 12 – 20 × 11 – 9 × 10
= 360 – 220 – 90
= 360 – 310 = 50
Question : 3
The average of 15 numbers is 7. If the average of the first 8 numbers be 6.5 and the average of last 8 numbers be 9.5, then the middle number is
a) 21
b) 18
c) 23
d) 20
Answer »Answer: (c)
Using Rule 1,
The middle number
= 8 × 6.5 + 8 × 9.5 – 15 × 7
= 52 + 76 – 105
= 128 – 105 = 23
Question : 4
Out of four numbers, the average of the first three is 15 and that of the last three is 16. If the last number is 19, the first is
a) 15
b) 18
c) 16
d) 19
Answer »Answer: (c)
Using Rule 1,
a + b + c = 45 and
b + c + d = 48
⇒ b + c = 48 – 19 = 29
∴ a + b + c = 45
⇒ a = 45 – 29 = 16
Question : 5
The mean of 11 numbers is 35. If the mean of first 6 numbers is 32 and that of the last 6 numbers is 37, find the sixth number.
a) 29
b) 27
c) 30
d) 28
Answer »Answer: (a)
Using Rule 1,
Average of two or more numbers/quantities is called the mean of these numbers, which is given by
$\text"Average(A)" = \text"Sum of observation / quantities"/\text"No of observation / quantities"$
∴ S = A × n
Sixth number
= 6 × 32 + 6 × 37 – 11 × 35
= 192 + 222 – 385 = 29
Question : 6
The average of the largest and smallest 3 digit numbers formed by 0, 2 and 4 would be
a) 213
b) 303
c) 222
d) 312
Answer »Answer: (d)
Largest 3–digit number formed by 0, 2 and 4 = 420 Smallest number of three digits = 204
∴ Required average
= ${420+204}/2$ = $624/2$ = 312
GET average PRACTICE TEST 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
average Shortcuts and Techniques with Examples
-
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 …
Verbal Reasoning
Question & Answer Quiz
Non Verbal Reasoning
Question & Answer Quiz
Quantitative Aptitude
Question & Answer Quiz
Computer MCQ
Question & Answer Quiz
General English
Question & Answer Quiz
History GK
Question & Answer Quiz
Polity GK
Question & Answer Quiz
Geography GK
Question & Answer Quiz
Economy GK
Question & Answer Quiz
General Awareness GK
Question & Answer Quiz
Recently Added Subject & Categories For All Competitive Exams
100+ Quadratic Equation Questions Answers PDF for Bank
Quadratic Equation multiple choice questions with detailed answers for IBPS RRB SO. more than 250 Attitude practice test exercises for all competitive exams
Continue Reading »
IBPS Aptitude Linear Equations MCQ Questions Answers PDF
Linear equations multiple choice questions with detailed answers for IBPS RRB SO. more than 250 Attitude practice test exercises for all competitive exams
Continue Reading »
New 100+ Compound Interest MCQ with Answers PDF for IBPS
Compound Interest verbal ability questions and answers solutions with PDF for IBPS RRB PO. Aptitude Objective MCQ Practice Exercises all competitive exams
Continue Reading »
100+ Mixture and Alligation MCQ Questions PDF for IBPS
Most importantly Mixture and Alligation multiple choice questions and answers with PDF for IBPS RRB PO. Aptitude MCQ Practice Exercises all Bank Exams
Continue Reading »