CDS · Elementary Mathematics · UPSC · 2016–2026

LCM & HCF — CDS Elementary Mathematics PYQs

50 questions from this chapter, asked in 10 CDS exams between 2016–2026.

50questions
10CDS exams
2016–2026years covered

Questions asked per year

Practice questions

Q1MCQ2026

If the HCF of and is , then which of the following statements is/are correct?
I. HCF of and is
II. HCF of , is

Select the answer using the code given below:

(A)I only
(B)II only
(C)Both I and II
(D)Neither I nor II
Q2MCQ2026

The HCF and LCM of two numbers and are 44 and 4620 respectively. When is divided by 55, the quotient is 4 and remainder is 0. What is the value of ?

(A)770
(B)924
(C)1155
(D)2310
Q3MCQ2026

What is the LCM of 3.6, 0.009, 0.27?

(A)5.4
(B)10.8
(C)16.2
(D)21.6
Q4MCQ2026

What is the greatest possible speed at which a person can walk 13.3 km and 20.9 km so that the time (in hours) required in each case is a whole number?

(A)1.7 km/h
(B)1.9 km/h
(C)2.1 km/h
(D)2.3 km/h
Q5MCQ2026

A Question is given followed by two Statements I and II. Consider the Question and the Statements and mark the correct option.
Question: LCM of three numbers , and is 30 and their HCF is 5. What is the product of the three numbers?
Statement-I:
Statement-II:

Which one of the following is correct in respect of the above Question and the Statements?

(A)The Question can be answered by using one of the Statements alone, but cannot be answered using the other Statement alone
(B)The Question can be answered by using either Statement alone
(C)The Question can be answered by using both the Statements together, but cannot be answered using either Statement alone
(D)The Question can be answered even without using both the Statements
Q6MCQ2025

What is the HCF of the polynomials and ?

(A)1
(B)
(C)
(D)
Q7MCQ2025

Consider the following statements in respect of prime numbers and :
I. Their LCM is always an odd number.
II. Sum of their LCM and HCF is always an even number.
Which of the statements given above is/are correct?

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

The HCF of and is . Consider the following statements in respect of the HCF of and :
I. The HCF of and can be .
II. The HCF of and can be .
Which of the statements given above is/are correct?

(A)I only
(B)II only
(C)Both I and II
(D)Neither I nor II
Q9MCQ2025

What is the HCF of and ?

(A)
(B)
(C)
(D)1
Q10MCQ2025

What is the LCM of , and ?

(A)
(B)
(C)
(D)

Why practise LCM & HCF PYQs?

LCM & HCF has appeared in 10 CDS Elementary Mathematics exams we track between 2016–2026. 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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