Reasoning

Number Systems and Series

143 Questions

Number systems and series questions assess the ability to manipulate numerical values and spot patterns. The focus includes digit arrangements, binary conversions, and identifying largest or smallest numbers. These reasoning tasks are common across major competitive examinations.

Digit manipulationLargest and smallest numbersBinary number systemsPositional numeral systemsNumber series ranking

Number Systems and Series Questions

Multiple choice general knowledge math & puzzles
  1. 6199

  2. 4259

  3. 3257

  4. 6174

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This refers to Kaprekar's constant for 4-digit numbers. If you repeat the process of subtracting the smallest number from the largest number formed by the digits, you will always eventually reach 6174. The other numbers provided are not fixed points for this algorithm.

Multiple choice general knowledge math & puzzles
  1. Power

  2. Highest level of change

  3. Everything

  4. Thought

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In numerology, the digit 9 represents the highest level of change, completion, and culmination. It symbolizes the end of a cycle before a new one begins, and is associated with humanitarianism and universal love.

Multiple choice general knowledge math & puzzles
  1. True

  2. False

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

To answer this question, we need to understand that reading numbers backwards means that we read them from right to left. So, if we read the numbers 3-7-2-4-8-1-5 from right to left, we get 5-1-8-4-2-7-3. Therefore, the answer is A) True.

Correct Option: A

Explanation for the Correct Option:

The correct option is A because if we read the numbers 3-7-2-4-8-1-5 from right to left, we get 5-1-8-4-2-7-3. This is because reading numbers backwards means that we read them from right to left.

Multiple choice general knowledge math & puzzles
  1. 80

  2. 81

  3. 83

  4. 84

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

To form a three-digit number with digits in ascending order from 1-9, we simply need to choose any 3 distinct digits - there's exactly one way to arrange them in ascending order. This is a combination problem: 9C3 = 9!/(3!×6!) = (9×8×7)/(3×2×1) = 84. The key insight is that choosing digits determines the arrangement uniquely.

Multiple choice general knowledge math & puzzles
  1. 14285

  2. 42700

  3. 42857

  4. 10000

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the 5-digit number be N. If we put 1 at the end, we get 10N + 1. If we put 1 at the beginning, we get 100000 + N. The condition says 100000 + N = 3(10N + 1), which simplifies to 100000 + N = 30N + 3, giving 99997 = 29N, so N = 42857.

Multiple choice general knowledge
  1. Binary System

  2. Barter System

  3. Number System

  4. Hexa Dexcimal System

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Binary System uses only two digits: 0 and 1. This is the fundamental number system used in digital computing because electronic circuits can easily represent two states (on/off). Barter is an economic exchange system, not a number system.

Multiple choice general knowledge
  1. 18

  2. 19

  3. 20

  4. 21

  5. 22

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the triangular number sequence. The pattern shows the differences: 3-1=2, 6-3=3, 10-6=4, 15-10=5. Each difference increases by 1, so the next difference is 6, making the next number 15+6=21. Alternatively, these are 1, 1+2, 1+2+3, 1+2+3+4, 1+2+3+4+5.

Multiple choice general knowledge math & puzzles
  1. 32567

  2. 42859

  3. 42857

  4. 42569

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If the number is x, then 100000 + x is the number with 1 in front, and 10x + 1 is the number with 1 behind. The equation is 3(100000 + x) = 10x + 1. Solving gives 7x = 299999, so x = 42857.

Multiple choice general knowledge
  1. 1 and 4

  2. 4 and 5

  3. 2 and 4

  4. 2 and 3

  5. 1 and 5

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Counting frequency in: 2 3 4 2 1 3 4 2 8 7 5 2 1 3 4 6 2 3 4 1 9 5 3. 2 appears 5 times, 3 appears 5 times, 4 appears 4 times, 1 appears 3 times, 5 appears 2 times. Therefore, 2 and 3 have the maximum frequency (5 each), making Option D correct.

Multiple choice general knowledge sports
  1. 1113213211

  2. 1132123111

  3. 1331222211

  4. 1211121131

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is the 'look-and-say' sequence: 1 is read as 'one 1' -> 11, 11 is 'two 1s' -> 21, 21 is 'one 2, one 1' -> 1211, etc. Continuing: 13112221 is 'one 1, one 3, two 1s, three 2s, one 1' -> 1113213211. The sequence describes the digits in the previous term.

Multiple choice general knowledge math & puzzles
  1. 37648

  2. 21734

  3. 42857

  4. 74329

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the 5-digit number be N. If we put 1 at the beginning, we get 100000 + N. If we put 1 at the end, we get 10N + 1. According to the problem: (10N + 1) = 3 × (100000 + N). Solving: 10N + 1 = 300000 + 3N → 7N = 299999 → N = 42857. Verification: 142857 ÷ 428571 = 1/3. The other options don't satisfy this mathematical relationship.