Aptitude Questions : Averages Set 7

Hello Aspirants. Welcome to Online Quantitative Aptitude Section with explanation in AffairsCloud.com. Here we are creating question sample in Averages, which is common for all the IBPS, SBI exam and other competitive exams. We have included Some questions that are repeatedly asked in bank exams !!!

1. The average age of a husband and his wife was 25 years when they were married 7 years ago. Now the average age of husband, wife and his son is 23 years. Find the age of son now.
   1.3yr
   2.4yr
   3.5yr
   4.6yr
   5.None of these
   

   Answer & Explanation

   Answer – 3.5yr
   Explanation :
   (h+w – 14)/2 = 25
   H+w = 64
   Now, (h+w+s)/3 = 23
   S = 69-64 = 5 years
   
   
   
2. The average of 10 reading is 25.5. In this the average of first three is 20 and the next four is 26. If the eight reading is 5 less than the night one and also 8 less than the tenth one, then find the eight reading?
   1.22
   2.24
   3.26
   4.28
   5.None of these
   

   Answer & Explanation

   Answer – 3.26
   Explanation :
   sum of all ten reading = 255
   sum of first three = 60 and sum of next 4 = 104.
   Sum of 8^th, 9^th and 10^th reading = 91 = 3*x + 13
   X = 26
   
   
   
3. The average of first and second number is 25 more than the average off the second and third number. Find the difference between the first and the third number
   1.20
   2.30
   3.40
   4.50
   5.None of these
   

   Answer & Explanation

   Answer – 4.50
   Explanation :
   (a+b)/2 = 25 + (b+c/2)
   
   
   
4. In a hostel there are 30 students and if the number of students increased by 5 then the expense is increased by 40 per day. But the average expenditure diminishes by 3. Find the original expenditure.
   1.810
   2.870
   3.910
   4.950
   5.None of these
   

   Answer & Explanation

   Answer – 2.870
   Explanation :
   Let average expenditure be P.
   (30*P + 40)/35 = P-3
   P = 29. So expenditure = 29*30 = 870
   
   
   
5. The average age of a class is 19 years. While the average age of boys is 20 and the average age of girls is 17. If the number of boys is 20 then find the number of girls in the class
   1.10
   2.15
   3.16
   4.18
   5.None of these
   

   Answer & Explanation

   Answer – 1.10
   Explanation :
   Average of class = 19 = Sum/(b+g)
   sum (girls) = g*17
   sum (boys) = b*20
   19b + 19g = 17g + 20b
   2g = b = 20. So girls = 10
   
   
   
6. The average age of a family of 4 members 3 years ago is 21 years. A baby is born and now the average age of the family is same as before. Find the age of baby.
   1.8yrs
   2.9yrs
   3.10yrs
   4.11yrs
   5.None of these
   

   Answer & Explanation

   Answer – 2.9yrs
   Explanation :
   (X-12)/4 = 21
   X = 96. Now, (96+baby)/5 = 21
   Baby = 9yrs
   
   
   
7. The average height of 50 students in a class is 165cm. On a particular day, three students P,Q and R are absent, so the average of the remaining students becomes 163cm. If the height of P and Q is equal and height of R is 2 cm less than P, then find the height of P.
   1.187
   2.192
   3.197
   4.198
   5.None of these
   

   Answer & Explanation

   Answer – 3.197
   Explanation :
   sum of height (50) = 50*165 = 8250
   sum of height (47) = 47*163 = 7661
   sum of the height of P, Q and R = 8250-7661 = 589
   P+P+P-2 = 589 (as height of P is equal to Q and height of R = P -2)
   P = 197
   
   
   
8. The average age of a committee of 12 members is 48 years. A member of the committee age 62 retired and in place of him a new person aged 26 joined the committee. Find the new average of the committee.
   1.44
   2.45
   3.46
   4.48
   5.None of these
   

   Answer & Explanation

   Answer – 2.45
   Explanation :
   Total age of committee = 48*12
   new total age of committee = (48*12 – 62 + 26)/12 = 45
   
   
   
9. The average weight of 12 people gets increased by 3.5kg when a person weighs 56 kg got replaced by another man. Find the weight of the new man
   1.90kg
   2.92kg
   3.96kg
   4.98kg
   5.None of these
   

   Answer & Explanation

   Answer – 4.98kg
   Explanation :
   Let the weight of new man is x kg.
   (12p – 56 + x)/12 = p + 3.5 [12p is the total weight of 12 people]
   X = 98kg
   
   
   
10. In an examination the average marks of risha is 74. If she got 16 more marks in hindi and 20 more marks in English then her average would have been 78. Find the total number of subjects he studied?
    1.7
    2.8
    3.9
    4.10
    5.None of these
    

    Answer & Explanation

    Answer – 3.9
    Explanation :
    Let total subjects are P.
    Then, (74p + 20 + 16)/p = 78
    So, P = 9