Quantitative Aptitude

Number System and Digits

380 Questions

Number system and digits questions test the ability to manipulate numbers, identify significant digits, and form specific values. These problems often require finding missing digits or determining the properties of large sums. They form a vital component of the quantitative aptitude section.

Number formationMissing digitsSignificant digitsLargest and smallest numbersDigit sum properties

Number System and Digits Questions

Multiple choice

What is the sum of the largest and the smallest 5 digit number?

  1. 99999

  2. 10099

  3. 109999

  4. 10000

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Smallest 5 digit number = 10000 Largest 5 digit number = 99999                                                                                                                                                                               The sum of the two numbers = 109999                                                    Hence, this option is the correct answer.

Multiple choice

Which digits are representative of all numbers?

  1. 0

  2. 1

  3. Both (1) and (2)

  4. 3
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the binary numbering system, every possible value can be represented using only the digits 0 and 1. These two digits are the fundamental building blocks of all data in digital computing.

Multiple choice

A period of 1000 years is known as

  1. a century

  2. a millennium

  3. an epoch

  4. a generation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A millennium is a period of 1000 years. In contrast, a century is 100 years, and a decade is 10 years. The term is derived from the Latin words 'mille' (thousand) and 'annus' (year).

Multiple choice

ISBN consists of

  1. 6 digits

  2. 7 digits

  3. 10 digits

  4. 13 digits
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The International Standard Book Number (ISBN) was expanded from 10 digits to 13 digits in 2007 to increase the available numbering capacity.

Multiple choice

The number of significant digit in 20340 is

  1. 4

  2. 5

  3. 3

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In 20340, if the trailing zero is not significant (most common interpretation), significant digits are 2, 3, 4 (total 4). If it were significant, there would be 5.

Multiple choice

Consider the given two statements S1 and S2 and choose the correct option.

S1: In the number 456238, the place value of the digit 5 is 50,000. S2: In the number 5624389, the face value of the digit 5 is 5.

  1. S1 is true and S2 is false.

  2. S1 is false and S2 is true.

  3. Both S1 and S2 are false.

  4. Both S1 and S2 are true.

  5. None of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

S1: In the number 456238, the place value of the digit 5 is 50,000. Place value of 5 = 5 x 10000 = 50,000 (True)   S2: In the number 5624389, the face value of the digit 5 is 5. Face value of a number is the number itself. (True)