Quants Questions : Averages Set 4

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 Husband and wife was 30yr, 4 yr ago. What will be their average age at present ?
   A)30
   B)34
   C)Cannot be determined
   D)None of these
   
   Answer

   Answer – B)34
   Explanation :
   Avg of H  and W age 4yr ago = 30
   Present avg age of H  and W = 30+4 = 34
   
   
   
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 ?
   A)100kg
   B)101kg
   C)102kg
   D)103kg
   
   Answer

   Answer – C)102kg
   Explanation :
   x/20 =60; x = 1200
   x/21 = 62; x = 1302
   1302 – 1200 = 102
   
   
   
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 ?
   A)37
   B)37.5
   C)36
   D)38
   
   Answer

   Answer – D)38
   Explanation :
   x/2 = 35; x = 70
   x/3 = 40; x = 120
   5 sub avg = (70+120)/5 = 38
   
   
   
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
   A)71
   B)73
   C)75
   D)76
   
   Answer

   Answer – D)76
   Explanation :
   {(15*75)-(35+46)+(38+63)} / 15 = (1125 – 81 + 101) / 15
   = 1145/15 = 76.33 = 76
   
   
   
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
   A)35.56
   B)35.85
   C)35.89
   D)35.69
   
   Answer

   Answer – C)35.89
   Explanation :
   Let third num = x, 1^st numb = 3x, second no = 3x/2
   [3x+(3x/2)+x] / 3 = 65.8
   11x/2 = 197.4
   X = (2×197.4) / 11 = 35.89
   
   
   
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
   A)75
   B)82
   C)45
   D)98
   
   Answer

   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
   
   
   
7. The average of 5 consecutive number is 58.Find the first number ?
   A)55
   B)56
   C)57
   D)58
   
   Answer

   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
   
   
   
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
   A)50
   B)64
   C)76
   D)74
   
   Answer

   Answer – D)74
   Explanation :50+(8*3) = 50 + 24 = 74.
   
   
   
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
   A)51.5
   B)52.5
   C)55.2
   D)55.8
   
   Answer

   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
   
   
   
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 ?
    A) 102
    B) 105
    C) 107
    D) 108
    
    Answer

    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