You can find all the CAT Number System questions from the previous papers with detailed video explanations on this page. The number system plays a crucial role in CAT quantitative section. There are many tricks, shortcuts and formulas that help you to solve the questions quickly. One can find those solving tips in the video solutions explained by CAT experts and IIM Alumni. Look no further to get resources for practising the CAT Number systems concept. Take free CAT mocks to understand the exam pattern and also you'll get a fair idea of how questions are asked. Download the CAT number systems questions PDF with detailed video solutions and practice to perform well in the quant section. And the best part is you can download the questions PDF for free without signing up. Click on the link below to download all the number system questions from CAT previous papers PDF.
Year | Weightage |
| 2024 | 8 |
| 2023 | 7 |
2022 | 4 |
2021 | 2 |
2020 | 9 |
2019 | 5 |
2018 | 4 |
CAT Number Systems is one of the important topics in the quantitative
aptitude section and it is vital to have a clear understanding of the
formulas related to them. Checking with the CAT exam syllabus will help you know similar other important topics. Also, enrolling in a CAT online coaching will help you maximize your preparation and save up time. To help the aspirants ace this topic, we have
made a PDF containing a comprehensive list of formulas, tips, and
tricks that you can use to solve number systems questions with ease
and speed. Click on the below link to download the CAT Number Systems formulas PDF.
1. Remainder Theorems Formulae
Fermat's Theorem - For any integer $$a$$ and prime number $$p$$, $$a^p-a$$ is always divisible by $$p$$
Wilson's Theorem - For a prime $$p$$, remainder when $$(p-1)!$$ i divided by $$p$$ is $$(p-1)$$
Euler's Theorem - If M and N are co-prime to each other then the remainder when $$M^{\phi(N)}$$ is divided by N is 1
2. HCF and LCM
HCF * LCM of two numbers = Product of two numbers
The greatest number dividing a, b and c leaving remainders of $$x_1$$, $$x_2$$ and $$x_3$$ is the HCF of (a-$$x_1$$), (b-$$x_2$$) and (c-$$x_3$$).
The greatest number dividing a, b and c (a<b<c) leaving the same remainder each time is the HCF of (c-b), (c-a), (b-a).
LCM of fractions = LCM of Numerators ÷ HCF of Denominators.
3. Number of trailing zeros
Number of trailing zeros of n! in base b(b=$$p^m$$, where p is a prime number) is for $$k\ge1$$ $$\frac{1}{m}\left(\Sigma\left[\frac{n}{p^k}\right]\ \right)$$
In a 3-digit number N, the digits are non-zero and distinct such that none of the digits is a perfect square, and only one of the digits is a prime number. Then, the number of factors of the minimum possible value of N is
correct answer:-6
For a 4-digit number (greater than 1000), sum of the digits in the thousands, hundreds, and tens places is 15. Sum of the digits in the hundreds, tens, and units places is 16. Also, the digit in the tens place is 6 more than the digit in the units place. The difference between the largest and smallest possible value of the number is
correct answer:-1
The sum of digits of the number $$(625)^{65} \times (128)^{36}$$ is
correct answer:-25
The sum of all the digits of the number $$(10^{50}+10^{25}-123)$$, is
correct answer:-2
The number of divisors of $$(2^{6}\times 3^{5}\times 5^{3}\times 7^{2})$$, which are of the form $$(3r+1)$$, where r is a non-negative integer, is
correct answer:-4
If $$12^{12x}\times 4^{24x+12}\times 5^{2y}=8^{4z}\times 20 ^{12x} \times 243^{3x-6}$$, where x , y and z are
natural numbers, then $$ x + y + z $$ equals
correct answer:-112
The average of three distinct real numbers is 28. If the smallest number is increased by 7 and the largest number is reduced by 10, the order of the numbers remains unchanged, and the new arithmetic mean becomes 2 more than the middle number, while the difference between the largest and the smallest numbers becomes 64.Then, the largest number in the original set of three numbers is
correct answer:-70
If $$10^{68}$$ is divided by 13, the remainder is
correct answer:-3
When $$10^{100}$$is divided by 7, the remainder is
correct answer:-2
The sum of all real values of k for which $$\left(\cfrac{1}{8}\right)^{k}\times \left(\cfrac{1}{32768}\right)^{\cfrac{1}{3}}=\cfrac{1}{8}\times \left(\cfrac{1}{32768}\right)^{\cfrac{1}{k}}$$, is
correct answer:-3
The sum of all four-digit numbers that can be formed with the distinct non-zero digits a, b, c, and d, with each digit appearing exactly once in every number, is 153310 + n, where n is a single digit natural number. Then, the value of (a + b + c + d + n) is
correct answer:-31
If $$m$$ and $$n$$ are natural numbers such that $$n > 1$$, and $$m^n = 2^{25} \times 3^{40}$$, then $$m - n$$ equals
correct answer:-4
When $$3^{333}$$ is divided by 11, the remainder is
correct answer:-1
The number of all positive integers up to 500 with non-repeating digits is
correct answer:-378
Let a, b, m and n be natural numbers such that $$a>1$$ and $$b>1$$. If $$a^{m}b^{n}=144^{145}$$, then the largest possible value of $$n-m$$ is
correct answer:-4
Let n be the least positive integer such that 168 is a factor of $$1134^{n}$$. If m is the least positive integer such that $$1134^{n}$$ is a factor of $$168^{m}$$, then m + n equals
correct answer:-2
For any natural numbers m, n, and k, such that k divides both $$m+2n$$ and $$3m+4n$$, k must be a common divisor of
correct answer:-3
The number of positive integers less than 50, having exactly two distinct factors other than 1 and itself, is
correct answer:-15
The sum of the first two natural numbers,
each having 15 factors (including 1 and the number itself), is
correct answer:-468
The number of coins collected per week by two coin-collectors A and B are in the ratio 3 : 4. If the total number of coins collected by A in 5 weeks is a multiple of 7, and the total number of coins collected by B in 3 weeks is a multiple of 24, then the minimum possible number of coins collected by A in one week is
correct answer:-42
Video solutions can be a helpful resource for candidates preparing for CAT Number Systems questions. They can provide a step-by-step explanation of how to solve the problem, helping candidates better understand the concept and formula. Also, one can find various tips, tricks and shortcuts to solve the questions quickly.
Usually, the questions in the CAT from Number systems are moderately tricky. But not so tough if you are well versed with the basics and practice a good number of questions from this topic.