Quantitative Aptitude: Average Questions Set 2

Averages Questions with Tricks Explanation for IBPS PO, SBI PO, NIACL, NICL, RBI Garde B, Dena Bank PO PGDBF, BOI, Bank of Baroda and other competitive exams.

1. If the sum of five consecutive odd numbers is 255 then find the sum of largest and smallest number.
   A) 102
   B) 100
   C) 98
   D) 106
   E) 155
   
   View Answer

   Option A
   Solution:
   SUm of 5 odd numbers = 255
   Average = 255/5 = 51
   47…..49…..51……53……55
   Average = 51
   Sum of largest and small number = 47+55 = 102
   
2. The average age of a couple at the time of marriage is 30. What is the average age of their family 5 years hence if their child was born 3 years after the marriage?
   A) 22
   B) 24
   C) 26
   D) 28
   E) 27
   
   View Answer

   Option B
   Solution:
   (60+5+5+2)/3 = 72/3 = 24
3. Find the sum of first 20 multiples of 5.
   A) 1150
   B) 1250
   C) 1050
   D) 1350
   E) 1080
   
   View Answer

   Option C
   Solution:
   First find the average and then multiply it by 20.
   5, 10, 15, 20…………100
   Average = (5+100)/2 = 105/2
   Sum = 105/2 * 20 = 1050
4. In a class of 25 students the average marks of all students is 48. If the marks of new student is added then average becomes 50. Find the marks of new student.
   A) 98
   B) 100
   C) 102
   D) 99
   E) 115
   
   View Answer

   Option B
   Solution:
   48 + (2*26) = 100
5. The average score of a batsman in 19 innings is 99. He wants to make his average 100 in his last match. Find the number of runs he has to score to achieve his target.
   A) 119
   B) 118
   C) 120
   D) 117
   E) 137
   
   View Answer

   Option A
   Solution:
   99 + (1*20) = 119 
6. The present age ratio of A and B is 3:2. 9 years hence this ratio becomes 9:7. Find the average of their age 5 years hence.
   A) 18
   B) 19
   C) 20
   D) 21
   E) 29
   
   View Answer

   Option B
   Solution:
   Present …                    3 : 2
   9 years hence…..          9 : 7
   Now see -> 3 + 6 = 9 and 2 + 5 = 7. So first make their difference same by mutiplying by 2 in (1)
   So Present                6 : 4
   9 years hence…..       9 : 7
   Now difference is 3each
   So 3 == 9
   1 == 3
   A = 6 = 18
   B = 4 = 12
   Average age of A and B after 5 years = (18+5 + 12+5)/2 = 20
7. Out of given 5 numbers, the average of first four is 26 and of the last 4 is 25. What will be the difference between the first and the last number?
   A) 4
   B) 3
   C) 2
   D) 1
   E) 5
   
   View Answer

   Option A
   Solution:
   Sum of first four = 26*4 = 104
   Sum of last four = 25*4 = 100
   Difference = 104-100 = 4
8. A man bought 13 shirts of Rs 50 each, 15 pants of Rs 60 each and 12 pairs of shoes at Rs 65 a pair. Find the average value of all the articles.
   A) 38.25
   B) 48.25
   C) 58.25
   D) 68.52
   E) 35.45
   
   View Answer

   Option C
   Solution:
   (13*50 + 15*60 + 12*65)/(13+15+12) = 58.25 
9. The average of three numbers is 77. The first is twice the second and the second number is twice the third. The first number is
   A) 33
   B) 66
   C) 77
   D) 132
   E) 116
   
   View Answer

   Option D
   Solution:
   4x+2x+x = 7x = 77*3 = 231
   x = 33
   3x= 33*4 = 132
10. The average temperature from Monday to Wednesday is 37°C. While the average temperature from Tuesday to Thursday is 34°C. The temperature of Thursday is 4/5 times to that of Monday. Find the temperature of Thursday.
    A) 36°C
    B) 37°C
    C) 33°C
    D) 34°C
    E) 38°C
    
    View Answer

    Option A
    Solution:
    (M+T+W)/3 = 37…..(1)
    (T+W+Th)/3 = 34
    Th = 4/5 * M
    (T + w + 4M/5)/3 = 34
    So T + w + 4M/5 = 102…..(2)
    From (1) and (2), M = 45
    So Th = 4/5 * 45 = 36

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