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 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.

Multiple choice

What is the LCM of 16 and 22?

  1. 176

  2. 164

  3. 148

  4. 124
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Prime Factors of 16 = 2 x 2 x 2 x 2 Prime Factors of 22 = 2 x 11 Lowest common multiple = 24 x 11 = 176

Multiple choice

What is the HCF of 96 and 118?

  1. 1

  2. 2

  3. 4

  4. 6
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Factors of 96 = 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 96 Factors of 118 = 1, 2, 59, 118 Common factors = 1 and 2 HCF of 96 and 118 = 2

Multiple choice

What is the LCM of 6 and 9?

  1. 6

  2. 12

  3. 18

  4. 36
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Multiples of 6 are 6, 12, 18, 24, 36, 42, 48, 54, 60.... Multiples of 9 are 9, 18, 27, 36, 45, 54, 63, 72, 81, 90....... Common multiples = 18, 36, 54 LCM of 6 and 9 is 18.

Multiple choice

Find the LCM of (a + b)2 and (a + b).

  1. (a + b)

  2. (a + b)2

  3. (a + b)3

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

Find LCM of (a+b)² and (a+b). Since (a+b)² = (a+b)(a+b), it's already a multiple of (a+b). The LCM of a quantity and its square is always the square itself. LCM = (a+b)².

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) = (x2 - z2)