Aptitude - Number System Online Quiz


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Following quiz provides Multiple Choice Questions (MCQs) related to Number System. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Questions and Answers

Q 1 - What is the result of the following?

 4 + 44 + 444 + 4.44 

A - 486.44

B - 444

C - 496.44

D - 44

Answer : C

Explanation

496.44

Q 2 - Which of the numbers is exactly divisible by 3?

A - 415591

B - 6472

C - 3364

D - 413976

Answer : D

Explanation

Divisibility by 3: if sum of the digits is divisible by 3 then original number is divisible by 3. 413976, sum of digits is 30 thus the number is divisible by 3.

Q 3 - The difference of the squares of two consecutive even integers is divisible by which of the following integers?

A - 1

B - 5

C - 4

D - 2

Answer : C

Explanation

Let the consecutive integers(even) be 2p and (2p + 2):
= (2p + 2)2 - 2p2 = (2p + 2 + 2p)(2p + 2 -2p)
= 2(4p + 2)
= 4 (2p + 1)
Therefore, divisible by 4.

Q 4 - The sum of all two digit numbers divisible by 7 is?

A - 215

B - 535

C - 735

D - none of these

Answer : C

Explanation

7, 14, 21, ..., 98
A.P: a = 7, d = 7, l =98
tn = 98
= a + (n - 1)d
i.e. 98 = 7 + (n - 1)7
n = 14
Sum = n2 (a + l)
= 142 (7 + 98 )
= 735

Q 5 - 6 + 15 + 24 + 33 + ... + 123 = ?

A - 903

B - 603

C - 752

D - 690

Answer : A

Explanation

a = 6, d = 9, l = 123
Let number of terms be n
123 = a + (n - 1)d
123 = 6 + (n - 1)9
123 = 9n - 9
n = 14
Sn = n2 (a + l)
= 142 (6 + 123)
= 7 x 129
= 903

Q 6 - Which of the following number divides 461 + 462 + 463 + 464 completely?

A - 3

B - 10

C - 11

D - 13

Answer : B

Explanation

  461 + 462 + 463 + 464  = 460 x (41 + 42 + 43 + 44)  = 460 x (4 + 16 + 64 + 256)  = 460 x 340  which is divisible by 10.  

Q 7 - 1014 x 986 = y. What is y?

A - 988804

B - 998814

C - 998904

D - 999804

Answer : D

Explanation

 y =1014 x 986 = 1014 x (1000 - 14) = 1014000 - 14196 = 999804  

Q 8 - 217 x 217 + 183 x 183 = y. What is y?

A - 79698

B - 80578

C - 80698

D - 81238

Answer : B

Explanation

  y = 217 x 217 + 183 x 183    = (217)2 + (183)2  = (200 + 17)2 + (200 -17)2  Using formulae (a+b)2 = a2 + b2 + 2ab and  (a-b)2 = a2 + b2 - 2ab  (a+b)2 + (a-b)2 = 2(a2 + b2)  ∴ y = 2 x [(200)2 + (17)2]  = 2 x [40000 + 289]  = 2 x 40289  = 80578  

Q 9 - What is the largest number which can divide n3 - n for every natural number n?

A - 2

B - 3

C - 6

D - 12

Answer : A

Explanation

  (2)3 - 2 = 6   ∴ 6 is the largest number which can divide n3 - n for every natural number n.  

Q 10 - (6n2 + 6n) is always divisible by?

A - 6 only

B - 6 and 12 both

C - 18 only

D - 24 only

Answer : B

Explanation

  6n2 + 6n = 6(n)(n+1)  As n(n+1) is always even so number is divisible by 12 as well.  



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