Quants Questions : Number System Set 5

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

1. The sum of 3 consecutive even number is 40 more than the average of these numbers. Which of the following is the 2^nd largest number ?
   A)18
   B)20
   C)22
   D)24
   
   Answer

   B)20
   Explanation :
   X+x+2+x+4 = 40+(x+x+2+x+4)/3
   3x+6 = 40+ (3x+6)/3
   (9x+18 – 3x-6)/3= 40
   6x + 12 = 120
   X = 108/6 = 18
   18+2 = 20
   
   
   
2. The sum of 3 consecutive number is 1251, Find the largest even number ?
   A)420
   B)414
   C)418
   D)416
   
   Answer

   C)418
   Explanation :
   X+x+1+x+2 = 1251
   3x+3 = 1251
   X = 1248/3 = 416
   X+2 = 416+2 = 418
   
   
   
3. What is the least number that can be added to 7218 make it a perfect square ?
   A)7
   B)5
   C)6
   D)4
   
   Answer

   A)7
   Explanation :
   85*85 = 7225
   
   
   
4. If a = -2 and b = -5 then find the value of  a³ + b³ – a² + b² + 2a – 3b
   A)-98
   B)-100
   C)101
   D)-101
   
   Answer

   D)-101
   Explanation :
   a³ + b³ – a² + b² + 2a – 3b
   (-2)³ + (-5) ³ – (-2)² + (-5)² + 2(-2) – 3(-5) = -8 -125-4+25-4+15 = -101
   
   
   
5. x+(1/x) = 2, then find the value of x¹⁰ + (-1/x)¹⁰
   A)0
   B)1
   C)2
   D)3
   
   Answer

   C)2
   Explanation :
   X²+1 = 2x
   X²– 2x+1 = 0
   X= 1
   x¹⁰ + (-1/x)¹⁰ = 1+1 = 2
   
   
   
6. The average of 7 consecutive number is n, if the next 2 number also included then the new average will be increased by ?
   A)0
   B)1
   C)2
   D)3
   
   Answer

   B)1
   Explanation :
   Avg of 7 no= (7+1)/2 = 8/2 = 4
   Avg of 9 no = (9+1)/2 = 5
   5- 4 = 1
   Hence increased by 1
   
   
   
7. When a positive number n is divided by 7 leaves the remainder 2, when 3n is divided by the same number, then the remainder is
   A)4
   B)5
   C)6
   D)8
   
   Answer

   C)6
   Explanation :
   N = 7+2 =9
   3n = 27
   27/7 = 6
   
   
   
8. The number of prime factors of 510510
   A)4
   B)5
   C)6
   D)7
   
   Answer

   D)7
   Explanation :2*3*5*7*11*13*17 = 510510
   
   
   
9. Which one cannot be the square of a natural number ?
   A)2116
   B)2304
   C)2202
   D)2209
   
   Answer

   C)2202
   Explanation :Square number can never end in 2,7
   
   
   
10. 25% of a number is 2 time 65% of another number.Find the ratio of the second no to the first number ?
    A)5:26
    B)26:5
    C)23:7
    D)5:23
    
    Answer

    A)5:26
    Explanation :
    (a*25)/100 = b(2*65)/100
    a*25 = b*130
    a/b = 130/25 = 26/5
    b:a = 5:26
    
    
    

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