CDS · Elementary Mathematics · UPSC · 2016–2025

Number System — CDS Elementary Mathematics PYQs

240 questions from this chapter, asked in 10 CDS exams between 2016–2025.

240questions
10CDS exams
2016–2025years covered

Questions asked per year

Practice questions first 10 of 240 — free

Q1MCQ2025

What is the sum of all 3-digit numbers that give a remainder of 5 when they are divided by 50?

(A)9005
(B)9540
(C)9600
(D)9640
Q2MCQ2025

Let be the remainder when is divided by 342 and be the remainder when is divided by 344. What is equal to?

(A)0
(B)1
(C)2
(D)6
Q3MCQ2025

is the smallest 5-digit number which when divided by leaves a remainder 1. What is the value of ?

(A)12
(B)13
(C)14
(D)15
Q4MCQ2025

What is the minimum value of for which is an integer?

(A)729
(B)243
(C)27
(D)1
Q5MCQ2025

Consider a 2-digit number . Let be the product of the digits of the number. If is added to the square of the digit in the tens place of , we get 84. If is added to the square of the digit in the unit place of , we get 60. What is the value of ?

(A)100
(B)110
(C)115
(D)120
Q6MCQ2025

Given that is an integer. What is the largest value of for which this is true?

(A)20
(B)21
(C)24
(D)None of the above
Q7MCQ2025

There are two natural numbers and . When is divided by 12, it leaves a remainder 4. When is divided by 12, it leaves a remainder 6. Which of the following statements is/are correct?
I. The remainder when is divided by 12 is 10.
II. The remainder when is divided by 12 is 10.
Select the correct answer using the code given below:

(A)I only
(B)II only
(C)Both I and II
(D)Neither I nor II
Q8MCQ2025

What is the remainder when is divided by , where is a prime number?

(A)1
(B)2
(C)3
(D)4
Q9MCQ2025

What is the number of factors of ?

(A)33
(B)30
(C)28
(D)24
Q10MCQ2025

If , then what is the value of ?

(A)−1
(B)0
(C)1
(D)10

Why practise Number System PYQs?

Number System has appeared in 10 CDS Elementary Mathematics exams we track between 2016–2025. UPSC examiners consistently reuse concepts and question patterns from this topic — practising its previous year questions is the most reliable way to know exactly what to expect in your exam.

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