Quantitative Aptitude · Mathematics

HCF and LCM

215 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

Find the H.C.F. of 20 and 30.

  1. 2

  2. 3

  3. 10

  4. 20
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Factors of 20 = 1, 2, 4, 5, 10, 20 Factors of 30 = 1, 2, 3, 5, 6, 10, 15, 30 H.C.F. = 10

Multiple choice

What is the HCF of 375, 625 and 875?

  1. 25

  2. 100

  3. 125

  4. 126
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Factors of 375 = 5 × 5 × 5 × 3 Factors of 625 = 5 × 5 × 5 × 5 Factor of 875 = 5 × 5 × 5 × 7 HCF = 5 × 5 × 5 = 125

Multiple choice

What is the LCM of 54 and 78?

  1. 542

  2. 702

  3. 784

  4. 798

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

54, 78 Factors of 54 = 2 × 3 × 3 × 3 Factors of 78 = 2 × 3 × 13 LCM = 2 × 3 × 3 × 3 × 13 = 702

Multiple choice

What is the HCF of 74 and 84?

  1. 2

  2. 4

  3. 6

  4. 8
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Factors of 74 = 1, 2, 37, 74 Factors of 84 = 1, 84, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42 Common factor = 1, 2 Highest common factor of 74 and 84 is 2.

Multiple choice

What is the LCM of 8 and 14?

  1. 42

  2. 56

  3. 72

  4. 84
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Multiples of 8 = 8, 16, 24, 32, 40, 48, 56, 64, 72, 80 Multiples of 14 = 14, 28, 42, 56, 70, 84, 98, 112, 126, 140, 154 Lowest common multiple is 56.

Multiple choice

What is the LCM of 14 and 18?

  1. 72

  2. 86

  3. 94

  4. 126
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Multiple of 14 = 14, 28, 42, 56, 70, 84, 98, 112, 126, 140 Multiples of 18 = 18, 36, 54, 90, 108, 126, 144, 162, 180 Lowest common multiple of 14 and 18 = 126

Multiple choice

What is the HCF of 240 and 196?

  1. 24

  2. 16

  3. 4

  4. 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Factors of 240 = 1, 2, 3, 4, 6, 8, 10, 12, 15, 16, 20, 30, 24, 40, 60, 80, 120, 240, 5, 48 Factors of 196 = 1, 2, 4, 7, 14, 28, 49, 88, 196 Common factors = 1, 2, 4 HCF of 240 and 196 = 4

Multiple choice

What is the HCF of 120 and 160?

  1. 10

  2. 20

  3. 40

  4. 80
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Factors of 120 = 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60 Factors of 160 = 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 80, 160 Common factor = 1, 2, 3, 5, 8, 10, 20, 40 HCFof 120 and 160 is 40.

Multiple choice

What is the LCM of 19 and 21?

  1. 284

  2. 297

  3. 357

  4. 399
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Prime Factors of 19 = 1 x 19 Prime Factors of 21 = 3 x 7 LCM of 19 and 21 = 19 x 3 x 7 = 399

Multiple choice

What is the HCF of 156 and 96?

  1. 8

  2. 10

  3. 12

  4. 14
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Factors of 156 = 1, 2, 3, 4, 6, 12, 13, 36, 39, 53, 78, 156 Factors of 96 = 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96 Common factors = 1, 2, 3, 4, 6, 12 Highest common factors of 156 and 96 is 12.