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Quantitative Aptitude

AVERAGES MCQs

Averages

Total Questions : 3752 | Page 5 of 376 pages
Question 41.

In the first 10 overs of a cricket game, the run rate was only 3.2. What should be the run rate in the remaining 40 overs to reach the target of 282 runs?

  1.    6.25
  2.    6.5
  3.    6.75
  4.    7
 Discuss Question
Answer: Option A. -> 6.25

Required run rate = \(\left(\frac{282-(3.2\times10)}{40}\right)=\frac{250}{40}=6.25\)

Question 42.

A family consists of two grandparents, two parents and three grandchildren. The average age of the grandparents is 67 years, that of the parents is 35 years and that of the grandchildren is 6 years. What is the average age of the family?

  1.    \(28\frac{4}{7}\)
  2.    \(31\frac{5}{7}\)
  3.    \(32\frac{1}{7}\)
  4.    None of these
 Discuss Question
Answer: Option B. -> \(31\frac{5}{7}\)

Required average = \(\left(\frac{67\times2+35\times2+6\times2}{2+2+3}\right)\)


=\(\left(\frac{134+70+18}{7}\right)\)


=\(\frac{222}{7}\)


=\(31\frac{5}{7}years.\)

Question 43.

A grocer has a sale of Rs. 6435, Rs. 6927, Rs. 6855, Rs. 7230 and Rs. 6562 for 5 consecutive months. How much sale must he have in the sixth month so that he gets an average sale of Rs. 6500?

  1.    Rs. 4991
  2.    Rs. 5991
  3.    Rs. 6001
  4.    Rs. 6991
 Discuss Question
Answer: Option A. -> Rs. 4991

Total sale for 5 months = Rs. (6435 + 6927 + 6855 + 7230 + 6562) = Rs. 34009.


Therefore  Required sale = Rs. [ (6500 x 6) - 34009 ]


= Rs. (39000 - 34009)


   = Rs. 4991.

Question 44.

The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?

  1.    0
  2.    1
  3.    10
  4.    19
 Discuss Question
Answer: Option D. -> 19

Average of 20 numbers = 0.


Sum of 20 numbers (0 x 20) = 0.


It is quite possible that 19 of these numbers may be positive and if their sum is a then 20th number is (-a).

Question 45.

The average weight of 8 persons increases by 2.5 kg when a new person comes in place of one of them weighing 65 kg. What might be the weight of the new person?

  1.    76 kg
  2.    76.5 kg
  3.    85 kg
  4.    Data inadequate
  5.    None of these
 Discuss Question
Answer: Option C. -> 85 kg

Total weight increased = (8 x 2.5) kg = 20 kg.


Weight of new person = (65 + 20) kg = 85 kg.

Question 46.

The captain of a cricket team of 11 members is 26 years old and the wicket keeper is 3 years older. If the ages of these two are excluded, the average age of the remaining players is one year less than the average age of the whole team. What is the average age of the team?

  1.    23 years
  2.    24 years
  3.    25 years
  4.    None of these
 Discuss Question
Answer: Option A. -> 23 years

Let the average age of the whole team by x years.


 11x - (26 + 29) = 9(x -1)


 11x - 9x = 46


 2x = 46


x = 23.


So, average age of the team is 23 years.

Question 47.

The average monthly income of P and Q is Rs. 5050. The average monthly income of Q and R is Rs. 6250 and the average monthly income of P and R is Rs. 5200. The monthly income of P is:

  1.    3500
  2.    4000
  3.    4050
  4.    5000
 Discuss Question
Answer: Option B. -> 4000

Let P, Q and R represent their respective monthly incomes. Then, we have:


P + Q = (5050 x 2) = 10100 .... (i)


Q + R = (6250 x 2) = 12500 .... (ii)


P + R = (5200 x 2) = 10400 .... (iii)


Adding (i), (ii) and (iii), we get:  2(P + Q + R) = 33000  or   P + Q + R = 16500 .... (iv)


Subtracting (ii) from (iv), we get P = 4000.


Therefore  P's monthly income = Rs. 4000.

Question 48.

The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is:

  1.    35 years
  2.    40 years
  3.    50 years
  4.    None of these
 Discuss Question
Answer: Option B. -> 40 years

Sum of the present ages of husband, wife and child = (27 x 3 + 3 x 3) years = 90 years.


Sum of the present ages of wife and child = (20 x 2 + 5 x 2) years = 50 years.


Therefore  Husband's present age = (90 - 50) years = 40 years.

Question 49.

A car owner buys petrol at Rs.7.50, Rs. 8 and Rs. 8.50 per litre for three successive years. What approximately is the average cost per litre of petrol if he spends Rs. 4000 each year?

  1.    Rs. 7.98
  2.    Rs. 8
  3.    Rs. 8.50
  4.    Rs. 9
 Discuss Question
Answer: Option A. -> Rs. 7.98

Total quantity of petrol 
consumed in 3 years = \(\left(\frac{4000}{7.50}+\frac{4000}{8}+\frac{4000}{8.50}\right)liters\)


\(=4000\left(\frac{2}{15}+\frac{1}{8}+\frac{2}{17}\right)liters\)


\(=\left(\frac{76700}{51}\right)liters\)


Total amount spent = Rs. (3 x 4000) = Rs. 12000.


Therefore Average Cost = Rs.\(\left(\frac{1700\times51}{76700}\right)=Rs.\frac{6120}{767}=Rs.7.98\)

Question 50.

In Aruns opinion, his weight is greater than 65 kg but less than 72 kg. His brother doest not agree with Arun and he thinks that Aruns weight is greater than 60 kg but less than 70 kg. His mothers view is that his weight cannot be greater than 68 kg. If all are them are correct in their estimation, what is the average of different probable weights of Arun?

  1.    67 kg.
  2.    68 kg.
  3.    69 kg.
  4.    Data inadequate
  5.    None of these
 Discuss Question
Answer: Option A. -> 67 kg.

Let Arun's weight by X kg.


According to Arun, 65 < X < 72


According to Arun's brother, 60 < X < 70.


According to Arun's mother, X <= 68


The values satisfying all the above conditions are 66, 67 and 68.


Therefore Required average = \(\left(\frac{66+67+68}{3}\right)=\left(\frac{201}{3}\right)=67kg.\)

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