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# Average - MCQ 5

## 20 Questions MCQ Test Quantitative Techniques for CLAT | Average - MCQ 5

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This mock test of Average - MCQ 5 for Quant helps you for every Quant entrance exam. This contains 20 Multiple Choice Questions for Quant Average - MCQ 5 (mcq) to study with solutions a complete question bank. The solved questions answers in this Average - MCQ 5 quiz give you a good mix of easy questions and tough questions. Quant students definitely take this Average - MCQ 5 exercise for a better result in the exam. You can find other Average - MCQ 5 extra questions, long questions & short questions for Quant on EduRev as well by searching above.
QUESTION: 1

### The average age of Husband and wife was 30yr, 4 yr ago. What will be their average age at present ?

Solution:

Answer – B)34 Explanation : Avg of H  and W age 4yr ago = 30 Present avg age of H  and W = 30+4 = 34

QUESTION: 2

### The average weight of 20 students is 60kg.If the weight of the teacher is added, average is increased by 2kg.What was the teacher’s weight ?

Solution:

Option ..( c)

The average weight of 20 students is 60 kg

Therfore, the total weight of 20 students = 20*60  = 1200 kg

When the teacher is added then average is increased by  2 kg

=>  Average weight  of 20 students and 1 teacher become  62 kg.

=>  Total weight of 20 students and 1 teacher :-

21 * 62 = 1302 kg

The required weight of teacher:-

=>  [ 1302  - 1200] kg  =  102 kg

So., the right answer is 102 kg.

QUESTION: 3

### The average mark in 2 subjects is 35 and in three other subject is 40.Then find the average mark in all the five matches ?

Solution:

Answer – D)38 Explanation : x/2 = 35; x = 70 x/3 = 40; x = 120 5 sub avg = (70+120)/5 = 38

QUESTION: 4

The average height of 15 students is calculated as 75. But later it was found that the height of 1 student wrongly entered as 35 instead of 38 and another as 46 instead of 63.The correct average is

Solution:

Answer – D)76 Explanation : {(15*75)-(35+46)+(38+63)} / 15 = (1125 – 81 + 101) / 15
= 1145/15 = 76.33 = 76

QUESTION: 5

Among the three number the first is thrice the third number and second number is half of the first number. If the average of the three number is 65.8 then find the third number

Solution:

Answer – C)35.89 Explanation : Let third num = x, 1 numb = 3x, second no = 3x/2 [3x+(3x/2)+x] / 3 = 65.8 11x/2 = 197.4 X = (2×197.4) / 11 = 35.89

QUESTION: 6

The average weight of 3 students P,Q and R is 84kg.Anothe students S joins the group and the average becomes 80kg. If another man T whose weight is 3kg more than that of S, replaces P, then the average weight of Q,R,S and T becomes 79 kg then the weight of P is

Solution:

Answer – A)75 Explanation : P+Q+R = 84*3 = 252
P+Q+R+S = 4*80 = 320
S = 320 – 252 = 68
Q+R+S+T = 79*4 = 316
Q+R+2S+3 = 316
S =68, Q+R =177
P = 252 – 177 = 75

QUESTION: 7

The average of 5 consecutive number is 58.Find the first number ?

Solution:

Answer – B)56 Explanation : X+x+1+x+2+x+3+x+4 = 58*5 = 290 5x+10 = 290 X = 290 – 10/5 = 280/5 = 56

QUESTION: 8

The average weight of 8 staff is increased by 3kg when one of them whose weight is 50kg is replaced by a new staff. The weight of the new staff is

Solution:

Answer – D)74 Explanation :50+(8*3) = 50 + 24 = 74.

QUESTION: 9

The average age of 15  army men is 60yrs.5 new army men of average age 30yrs join them. Find the new average age

Solution:

Answer – B)52.5 Explanation : 15 army men age = 15*60 =900 5 army men age = 5*30 = 150 New avg = 900+150/20 =52.5

QUESTION: 10

The average ages of 4 member, each having the age difference of 2yrs is 54 yrs.What is the sum of the youngest and oldest family member ?

Solution:

Answer – D) 108 Explanation : X+X+2+X+4+X+6 = 54*4 = 216
4X+12 = 216
X = 216-12/4 =51
X+6 = 51+6 = 57
Required = 51+57 = 108

QUESTION: 11

3 years ago, the average of a family of 5 members was 17 years. A baby having been born, the average age of the family is the same today. The present age of the baby is:

Solution:

Answer – B (2 years) Explanation – Total age of 5 members, 3 years ago = (17 x 5) years = 85 years Total age of 5 members now = (85 + 3 x 5) years = 100 years Total age of 6 members now = (17 x 6) years = 102 years Age of the baby = (102 – 100) years = 2 years

QUESTION: 12

Of the four numbers, the first is twice the second, the second is one-third of the third and the third is 5 times the fourth. The average of the numbers is 24.75.The largest of these numbers is:

Solution:

Answer – A (45) Explanation – Let the fourth number be a then hen, third number = 5a, second number= 5a/3 and first=10a/3 a+ 5a+ 5a/3 + 10/3 = 24.75 x 4 so,a=9 So, the numbers are 9, 45, 15 and 30

QUESTION: 13

The average age of students of a class is 15.8 years. The average age of boys in the class is 16.4 years and that of the girls is 15.4 years. The ratio of the number of boys to the number of girls in the class is:

Solution:

Answer – B (2 : 3) Explanation – Let the ratio be k:1 Then, k x 16.4 + 1 x 15.4 = (k + 1) x 15.8 (16.4 – 15.8) k = (15.8 – 15.4) k=2/3

QUESTION: 14

The average price of 10 books is Rs. 12 while the average price of 8 of these books is Rs. 11.75. Of the remaining two books, if the price of one book is 60% more than the price of the other, what is the price of each of these two books?

Solution:

Answer – A (Rs 10 and Rs 16) Explanation – Total price of the two books = Rs. [(12 x 10) – (11.75 x 8)] = Rs. (120 – 94) = Rs. 26 Let the price of one book be Rs.x Then, the price of other book = Rs. (x + 60% of x )= x + (3/5)x= (8/5)x so, x +(8/5)x=26 , x=10 The prices of the two books are Rs. 10 and Rs. 16

QUESTION: 15

The average age of 30 boys of a class is equal to 14 years. When the age of the class teacher is included the average becomes 15 years. Find the age of the class teacher?

Solution:

Answer – C (45) Explanation – Total ages of 30 boys = 14 x 30 = 420 years Total age when class teacher is included = 15 x 31 = 465 years Age of class teacher = 465 – 420 = 45 years

QUESTION: 16

The Average of marks obtained by 120 candidates in a certain examination is 35. If the average marks of passed candidates is 39 and that of failed candidates is 15, what is the number of candidates who passed the examination?

Solution:

Answer – B (100) Explanation – Let the number of passed candidates be a Then total marks =>120 x 35 = 39 a + (120 – a) x 15 4200 = 39 a + 1800 – 15 a a = 100

QUESTION: 17

The average of 11 results is 50. If the average of first 6 results is 49 and that of last 6is 52, find the sixth result?

Solution:

Answer – B (56) Explanation – The total of 11 results = 11 x 50 = 550 The total of first 6 results = 6 x 49 = 294 The total of last 6 results = 6 x 52 = 312 The sixth result is common to both: Sixth result = 294 + 312 – 550 = 56

QUESTION: 18

The average age of a family of 6 members is 22 years. If the age of the youngest member be 7 years, then what was the average age of the family at the birth of the youngest member?

Solution:

Answer – B (18) Explanation – Total age of all members = 6 x 22 = 132 years 7 years ago, total sum of ages = 132 – (6 x 7) = 90 years But at that time there were 5 members in the family Average at that time = 90 /5 = 18 years

QUESTION: 19

A batsman in his 17th innings makes a score of 85, and thereby increases his average by 3. What is his average after 17 innings?

Solution:

Answer – B (37) Explanation – Let the average after 16th innings be a, then total score after 17th innings => 16a+85 = 17 (a+3) a = 85-51 = 34 Average after 17 innings = a + 3 = 34 + 3 = 37

QUESTION: 20

There were 35 students in a hostel. If the number of students increase by 7, the expenses of the mess increase by Rs 42 per day while the average expenditure per head diminishes by Rs 1. Find the original expenditure of the mess?

Solution:

Answer – B (420) Explanation – Suppose the average expenditure was Rs a.
Then total expenditure = 35a When 7 more students join the mess, total expenditure = 35a + 42 Now, the average expenditure= (35a+42) / (35 + 7) Now, we have (35a + 42)/ 42 =(a – 1) or, 35a + 42 = 42a – 42 7a = 84 a = 12