Aptitude Test Preparation
Aptitude - Home
Aptitude - Overview
Quantitative Aptitude

Aptitude - Number System Online Quiz

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.

Q 1 - The unit digit in the product (636 x 924 x 368)?

Answer : C

Explanation

Unit Digit = Unit Digit in (6 x 4 x 8)
= 2

Q 2 - 115 x 115 + 85 x 85 = ?

Answer : C

Explanation

=(115)² + (85)²
=(100 + 15)² + (100 - 15)²
=2 x [(100)² + (15)²]
=20450
(Formula: (a+b)² + (a-b)² = 2(a² + b²))

Q 3 - On dividing a number by 56, we get remainder as 29. On dividing the same number by 8, what will be the remainder?

Answer : A

Explanation

Let p = number and q = quotient
p = 357 x q + 39
= (17 x 21 x q) + (17 x 2) + 5
= 17 x 921y + 2 ) + 5
Remainder = 5

Q 4 - It is being given that (2³²) + 1) is completely divisible by a whole number. Which of the following numbers is completely divisible by this number?

Answer : C

Explanation

Let 2³² = p
-> (2³² + 1) = p + 1
Let (p + 1) be completely divisible by natural number Z. Then->
(2⁹⁶ + 1) = [(2³²)³ + 1]
As (p³ + 1) = (p + 1)(p² - p + 1), which is completely divisible by Z, since (p + 1) is completely divisible by Z.

Q 5 - I how many ways can 22500 be written as a product of two different factors?

Answer : C

Explanation

150² = 22500
Therefore, 150² = ((2)(5)(3)(5))² = 2²5⁴3²
= ¹⁄₂{(2 + 1)(4 + 1)(2 + 1) - 1}
= 22

Q 6 - 1² - 2² + 3² - 4² +..+ 9² -10²?

Answer : D

Explanation

   Using formula a² - b² = (a-b)(a+b) 1² - 2² + 3² - 4² +..+ 9² -10² = (1-2)(1+2) + (3-4)(3+4) + (5-6)(5+6) + (7-8)(7+8) + (9-10)(9+10) = (-3) + (-7) + (-11) + (-11) + (-15) + (-19) = -55

Q 7 - (45 + 46 + 47 + ... + 114 + 115) = ?

Answer : C

Explanation

  Using formula for sum of natural numbers  (1 + 2 + 3 +... + n) = (1/2)n(n+1)  (45 + 46 + 47 + ... + 114 + 115) = (1 + 2 + 3 +... + 115) - (1 + 2 + 3 + ... + 44)  = (1/2) x 115 x 116 - (1/2) x 44 x 45  = 115 x 58 - 22 x 45  = 6670 - 990  = 5680

Q 8 - (y)² = 351649. What is y?

Answer : B

Explanation

  y = 1008 x 992     = (1000 + 8) x (1000 - 8)  Using formulae (a+b)(a-b) = a² - b²  ∴ y =  (1000)² - (8)²  = 1000000 - 64  = 999936

Q 9 - Which of the following is the smallest 3 digit prime number?

Answer : D

Explanation

101. (11)² *gt; 101 and 101 is not divisible by any of the following prime numbers 2,3,5 and 7.

Q 10 - The sum of digits of two digit number is 10 and difference between the digits is 2. What is the number?

Answer : A

Explanation

  let number be ab  Thus a + b = 10 and a - b = 2  => (a + b) + (a - b) = 12  => 2a = 12  => a = 6  => b = 10 - a  = 10 - 6 = 4  ∴ number is 64.