Quantitative Aptitude · Mathematics

HCF and LCM

233 Questions

Improve your quantitative aptitude speed by solving these HCF and LCM questions. The problems involve finding the highest common factor and least common multiple for sets of numbers. These calculations form a core part of the mathematics section in SSC, banking, and railway recruitment exams.

Finding HCFFinding LCMGreatest common factorLeast common multipleNumber properties

HCF and LCM Questions

Multiple choice

What is the HCF of 1470 and 220?

  1. 8

  2. 9

  3. 10

  4. 11
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Prime factorisation of 1470 = 2 × 3 × 5 × 7 × 7 Prime factorisation of 220 = 2 × 2 × 5 × 11 HCF of 1470 and 220 = 10

Multiple choice

Which of the following sets of the number has 72 as LCM?

  1. 14, 12, 18

  2. 16, 12, 14

  3. 12, 18, 24

  4. 18, 24, 28
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

12, 18, 24 Multiples of 12 = 12, 24, 36, 48, 60, 72, 84, ... Multiples of 18 = 18, 36, 54, 72, 90, ... Multiples of 24 = 24, 48, 72, 96, ..

LCM of 12, 18 and  24 = 72

Multiple choice

What is the LCM of x2 - z2 and x + z?

  1. (x + z) (x - z)

  2. (x + z)2

  3. (x - z)2

  4. (x - z)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Factors of x2 - z2 = (x + z) (x - z) Factors of (x + z) = (x + z) LCM = (x + z) (x - z)

Multiple choice

Find the smallest number which can exactly be divided by 6, 8, 12.

  1. 16

  2. 24

  3. 84

  4. 169
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Multiple of 6 - 6, 12, 18, 24, 30, 36, 42, 48, 54, 60 Multiple of 8 - 8, 16, 24, 32, 40, 48, 56, 64, 72, 80 Multiple of 12 - 12, 24, 36, 48, 60, 72, 84, 96, 108, 120 Common multiples are 24, 48 24 is the least common multiple of 6, 8 and 12