Quantitative Aptitude

Averages

1,527 Questions
All Basic average and reverse calculation 405 Adding or removing an observation 342 Weighted and combined averages 320 Replacement and correction of a recorded value 233 Ratio shortcut for two-group mixtures 111 Equal-distance average speed 59 Age, score, weight, and spending applications 32 Consecutive terms and arithmetic progressions 25

Averages Questions

Multiple choice maths profit-loss overhead expenses introduction to total cost price of the article profit and loss with overhead expenses

The average of the price per kg. of rice at $10$ different places was $Rs.4.85$. After a week, the price per kg. was increased by $20$ paise at $3$ places and decreased by $10$ paise at one place. The new average of price per kg is :

  1. $Rs. 4.88$
  2. $Rs. 4.86$
  3. $Rs. 4.90$
  4. $Rs. 5.35$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The initial total price for 10 places is 10 * 4.85 = Rs. 48.50. The total increase is (3 * 0.20) - (1 * 0.10) = 0.60 - 0.10 = Rs. 0.50. The new total is 48.50 + 0.50 = Rs. 49.00, giving a new average of 49.00 / 10 = Rs. 4.90.

Multiple choice mean and median mean maths assumed mean method assumed mean method of finding mean measure of central tendency

Mr. R purchases $20\ kgs$. of Wheat, $10\ kgs.$ of rice and $2\ kgs.$ of ghee every month. If the price of wheat is $Rs. 10$ per kg., price of rice is $Rs. 14$ per kg. and price of ghee is $Rs. 120$ per kg. Find the average price per kg. per month. Arithmetic mean $=$?

  1. $48$
  2. $18.125$
  3. $48.125$
  4. $18$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The average price per kg is the total cost divided by the total weight. Total cost = (20*10) + (10*14) + (2*120) = 200 + 140 + 240 = 580. Total weight = 20 + 10 + 2 = 32. Average = 580 / 32 = 18.125.

Multiple choice mean and median mean maths assumed mean method assumed mean method of finding mean measure of central tendency

The average marks of three batches of students having $70, 50$ and $30$ students respectively are $50, 55$ and $45$. Find the average marks of all the $150$ students, taken together.

  1. $50.67$
  2. $40.67$
  3. $50.60$
  4. $40.60$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The average marks of 70, 50 and 30 students respectively is 50, 55 and 45 marks. Therefore the total marks of 70, 50 and 30 students will be 70x50, 50x55, and 30x45 respectively. So the average marks of all the 150 students is 

= ( 3500 + 2750 + 1350 )/ ( 70+50+30)
= 7,600 / 150
= 50.67

Multiple choice mean and median mean maths assumed mean method assumed mean method of finding mean measure of central tendency

If the average weight of $150$ students is $60$ kg., what will be the number of boys and girls in the school if the average weight of boys and girls is $70$kg and $55$kg. respectively?

  1. $(50,100)$
  2. $(100,50)$
  3. $(40,110)$
  4. $(90,60)$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let B be the number of boys and G be the number of girls. B + G = 150. Total weight = 70B + 55G = 60 * 150 = 9000. Solving the system: 70B + 55(150-B) = 9000 -> 15B = 750 -> B = 50. Then G = 100.

Multiple choice computer and ms office mathematical methods for economics economics

While evaluating CA CPT papers an examiner has escaped the marks of one of the student while calculating the result summary of his class. However he knew that the average marks of the class was $72\%$ and the marks of the remaining students were $56, 85, 78, 70, 75, 48, 65, 85$ and $75$. The marks of the student were __________.

  1. $83$
  2. $82$
  3. $79$
  4. $81$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let the missing mark be x. There are 10 students total. The sum of the 9 known marks is 56+85+78+70+75+48+65+85+75 = 637. The total sum for 10 students with an average of 72% is 720. So, x = 720 - 637 = 83.

Multiple choice maths calculating and mental strategies 3 finding percentage of a number how many in all? problems on percentage

Choose the correct answer from the alternatives given.
Directions for question 71 to 75: Study the following table carefully and answer the questions given below.
Number of Students Enrolled
With Five Colleges over the Years

Year/College A B C D E
2004 450 320 400 480 520
2005 480 350 380 500 540
2006 420 300 410 520 460
2007 460 360 430 470 480
2008 470 340 390 530 530

What is the average number of students enrolled in the college A over the years? 

  1. $456$
  2. $460$
  3. $464$
  4. $452$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Total number of students in college over the years$=420+480+420+460+470=2280$

Average no. of students$=2280/5=456$

Multiple choice maths calculating and mental strategies 3 finding percentage of a number how many in all? problems on percentage

Choose the correct answer from the alternatives given.
The average age of eleven cricket players is 20 years. If the age of the coach is also included, the average age increases by 10%. The age of the coach is

  1. 48 year

  2. 44 year

  3. 40 year

  4. 36 year
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Average of 11 players $= 20$ years.
Sum of age of 11 players $= 20 \times 11 = 220$
Average age of players and coach $1.1 \times 20 22$ years
Sum of ages of players & coach $= 22 \times 12 = 264$ years.
Age of coach $= 264 - 220 = 44$ years. 

Multiple choice business economics and quantitative methods measures of dispersion and skewness quartile deviation or semi-interquartile range interquartile range histograms and frequency distribution diagrams

In a group, $2$ students spend Rs$8$ daily, $3$ students spend Rs$10$ daily and $5$ students spend Rs$6$ daily. The average spending of all $10$ students is _______.

  1. $7.6$
  2. $5.8$
  3. $8.5$
  4. $6.7$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Total spending = (2 * 8) + (3 * 10) + (5 * 6) = 16 + 30 + 30 = 76. Total students = 10. Average = 76 / 10 = 7.6.

Multiple choice maths operations adding and subtracting numbers using place value addition & subtraction mental additions and subtractions

The average weight of 7 men is diminished by 3 kg when one of them who weighs 73 kg is replaced by a new man then the weight of the new man is 

  1. 50 kg

  2. 52 kg

  3. 53 kg

  4. 54 kg
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The averages weight of seven man diminished by 3 kg .Then total weight diminished by $3\times 7=21 kg $

If one of them whose weight is 73 kg is replased by anew man 
Then weight of new man =72-21=52 kg

Multiple choice maths average arithmetic mean of ap introduction to averages means

The arithmetic mean (average) of a set of $50$ numbers is $38$. If two numbers, namely, $45$ and $55$, are discarded, the mean of the remaining set of numbers is :

  1. $36.5$
  2. $37$
  3. $37.2$
  4. $37.5$
  5. $37.52$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$Arithmetic\quad sum=\cfrac { sum\quad of\quad numbers }{ number\quad of\quad numbers } $
$\therefore S=50\times 38=1900;\quad \therefore x=\cfrac { 1900-45-55 }{ 48 } =37.5$

Multiple choice maths average arithmetic mean of ap introduction to averages means

In a Maths test the average score of the $10$ girls in a class is $15$ and the average score of the $15$ boys is $10$. The average score of the class in the test is 

  1. $12$
  2. $12.5$
  3. $13$
  4. $12.75$`
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The total score of 10 girls is 10 * 15 = 150. The total score of 15 boys is 15 * 10 = 150. The total class score is 300 for 25 students. The average is 300 / 25 = 12.

Multiple choice maths average arithmetic mean of ap introduction to averages means

Find the average of the following set of scores $253,124,255,534,836,375,101,443,760$

  1. $427$
  2. $413$
  3. $141$
  4. $409$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

To find the average, sum all the given scores and divide by the total count of numbers. The sum of 253, 124, 255, 534, 836, 375, 101, 443, and 760 is 3681, and dividing by 9 yields 409.

Multiple choice maths average arithmetic mean of ap introduction to averages means

The average age of $30$ girls. is $13\ yr$. The average of first $18$ girls is $15\ yr$. Find out the average age of remaining $12$ girls? 

  1. $12\ yr$
  2. $10\ yr$
  3. $16\ yr$
  4. $10.5\ yr$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Multiply the total count by the overall average to find the total sum of ages, which is 30 * 13 = 390. Next, find the sum of the ages of the first 18 girls by multiplying 18 * 15 = 270. Subtracting this from the total gives 390 - 270 = 120 for the remaining 12 girls, leading to an average of 120 / 12 = 10 years.

Multiple choice maths average arithmetic mean of ap introduction to averages means

A student bought $4$ books for $Rs.120$ from one book shop and $6$ books for $Rs.150$ from another. The average price (in  rupees), he paid per book was:

  1. $27$
  2. $27.50$
  3. $135$
  4. $138$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Total cost = 120 + 150 = 270. Total books = 4 + 6 = 10. Average price = 270 / 10 = 27.

Multiple choice maths average arithmetic mean of ap introduction to averages means

The average height of 25 boys is 1.4 m. When 5 boys leave the group, then the average height increases by 0.15 m. What is the average height of the 5 boys who leave?

  1. 0.8 m

  2. 0.9 m

  3. 0.95 m

  4. 1.05 m
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Initial total height = 25 * 1.4 = 35. New total height = 20 * 1.55 = 31. Total height of 5 boys = 35 - 31 = 4. Average = 4 / 5 = 0.8.