Number System Questions with Solutions

27 questions15 easy11 medium1 hard

The number system is the foundation of quantitative aptitude. It covers the different types of numbers (natural numbers, whole numbers, integers, rational and irrational numbers, primes and composites) and the rules that govern them. Exam questions test divisibility rules, unit digits of large powers, remainders, factors and multiples, HCF and LCM, and the number of trailing zeros in a factorial. Most of these questions can be solved in under a minute once you know the pattern. Unit digits repeat in cycles of four, and divisibility by 11 depends on the difference between the sums of alternate digits. Number properties also appear inside questions on simplification, averages and series, so strong basics here save time across the whole quant section. Practise the questions below to build speed with divisibility, remainders, unit digits and HCF-LCM. Every question has a step-by-step solution and, where possible, a shortcut method.

  1. Q1.

    The ratio between a two-digit number and the sum of the digits of that number is 4 : 1. If the digit in the unit's place is 3 more than the digit in the ten's place, then the number is

    A. 24B. 63C. 36D. 42
    easyAsked in NIMCET 2012View solution ›
  2. Q2.

    How many numbers from 1 to 100 are divisible by 8 and have at least one digit equal to 8?

    A. FourB. ZeroC. EightD. Six
    easyAsked in NIMCET 2010View solution ›
  3. Q3.

    How many numbers between 1 and 1000 (both excluded) are both squares and cubes?

    A. NoneB. 1C. 2D. 3
    easyAsked in NIMCET 2010View solution ›
  4. Q4.

    Find the remainder when is divided by .

    A. 153B. 33C. 73D. 187
    easyAsked in NIMCET 2009View solution ›
  5. Q5.

    Find the unit digit of .

    A. 1B. 3C. 7D. 9
    easyAsked in NIMCET 2009View solution ›
  6. Q6.

    When you reverse the digits of the number 13, the number increases by 18. How many other two-digit numbers increase by 18 when their digits are reversed?

    A. 5B. 6C. 7D. 8
    easyAsked in NIMCET 2009View solution ›
  7. Q7.

    Let be distinct integers, where and are odd positive integers and is an even positive integer. Which of the following cannot be true?

    A. is evenB. is oddC. is oddD. is even
    easyAsked in NIMCET 2008View solution ›
  8. Q8.

    Choose the correct option for the remainder when is divided by 24.

    A. 9B. 11C. 152D. 13
    easyAsked in NIMCET 2021View solution ›
  9. Q9.

    The greatest number which on dividing 1657 and 2037 leaves remainders 6 and 5 respectively is

    A. 127B. 235C. 123D. 305
    easyAsked in NIMCET 2022 +1View solution ›
  10. Q10.

    The remainder when is divided by 5 is

    A. 1B. 2C. 3D. 4
    easyAsked in NIMCET 2015View solution ›
  11. Q11.

    The last digit of the number obtained by multiplying the numbers 81 x 82 x 83 x 84 x 85 x 86 x 87 x 88 x 89 is

    A. 0B. 9C. 7D. 2
    easyAsked in NIMCET 2018View solution ›
  12. Q12.

    How many numbers between 1 and 1000 are divisible by all the numbers 2, 3, 4, 5 and 6?

    A. 16B. 32C. 17D. 33
    easyAsked in NIMCET 2018View solution ›
  13. Q13.

    Among the given numbers below, the smallest number which, when divided by 9, 10, 15 and 20, leaves the remainders 4, 5, 10 and 15 respectively, is

    A. 85B. 535C. 355D. 265
    easyAsked in NIMCET 2024View solution ›
  14. Q14.

    Ramu visits Delhi every 15 days and Samu goes to Delhi every 20 days. They met at Delhi 5 days back. After how many days, from today, will they meet at Delhi next time?

    A. 35B. 55C. 60D. 65
    easyAsked in NIMCET 2024View solution ›
  15. Q15.

    A two-digit number is such that the product of its digits is 12. If 36 is added to the number, the digits interchange their places. What is the number?

    A. 26B. 38C. 25D. 24
    easyAsked in NIMCET 2025View solution ›