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

Which of the following sets of numbers will have 80y2x as LCM?

  1. 4y2, 16x, 8y

  2. 2y2, 16xy, 8a

  3. 8y2, 16xy, 10y

  4. 18y2, 16xy, 4y
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

8y2, 16xy, 10y Factors of 8y2 = 2 × 2 × 2 × y × y Factors of 10y = 2 x 5 x y Factors of 16 × y = 2 × 2 × 2 × 2 × x × y LCM = 2 × 2 × 2 × 2 × 5 x x × y = 80xy2

Multiple choice

Which of the following sets of numbers have 140ab as LCM?

  1. 10ab, 20ab, 28ab

  2. 11ab, 21ab, 28ab

  3. 12ab, 20ab, 14ab

  4. 20ab, 26ab, 14ab
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

10ab, 20ab, 28ab Factors of 10ab = 2 × 5 × a × b Factors of 20ab = 2 × 2 × 5 × a × b Factors of 28ab = 2 × 2 × 7 × a × b LCM = 140ab

Multiple choice

Which of the following sets of numbers will have 560b4a as LCM?

  1. 28b, 20ab3, 16b4

  2. 28b, 20ab2, 16b4

  3. 20b2, 28ab, 18b4

  4. 28b4, 18ab3, 16b
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

28b2, 20ab3, 16b4 Factors of 28b2 = 2 × 2 × 7 × b × b Factors of 20ab3 = 2 × 2 × 5 × a × b × b × b Factors of 16b4 = 2 x 2 x 2 x 2 x b x b x b x b LCM = 2 × 2 × 7 × 5 × 2 × 2 × b × b × a × b × b = 560ab4

Multiple choice

Sam has two pieces of cloth. One piece is 72 inches wide and the other piece is 90 inches wide. She wants to cut both pieces into strips of equal width that are as wide as possible. How would she cut the strips?

  1. She should cut each piece to be 14 inches wide.

  2. She should cut each piece to be 16 inches wide.

  3. She should cut each piece to be 18 inches wide.

  4. She should cut each piece to be 20 inches wide.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 HCF of 72 and 90 = 18

Multiple choice

What is the LCM of 22, 54 and 108?

  1. 5442

  2. 2926

  3. 1188

  4. 428
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Factors of 22 = 2 × 11 Factors of 54 = 2 × 3 × 3 × 3 Factors of 108 = 2 × 2 × 3 × 3 × 3 LCM = 2 × 11 × 3 × 3 × 3 × 2 × 3 × 3 × 3 = 1188

Multiple choice

LCM of 4 is ______.

  1. 1

  2. 2

  3. 3

  4. Can't be determined
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

We always need at least two numbers to find the LCM.

Multiple choice

LCM of 15 and 9 is ______.

  1. 18

  2. 45

  3. 135

  4. 230
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Multiples of 15 = 15, 30, 45, 60 Multiples of 9 = 9, 18, 27, 36, 45, 54 LCM = 45

Multiple choice

LCM of 2 and 6 is ____.

  1. 2

  2. 6

  3. 12

  4. 18
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Multiples of 2 = 2, 4, 6, 8, 10, 12, 14 Multiples of 6 = 6, 12 LCM of 2 and 6 = 6

Multiple choice

HCF of 24 and 16 is ______.

  1. 8

  2. 16

  3. 24

  4. 32
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Factors of 24 = 2 × 2 × 2 × 3 Factors of 16 = 2 × 2 × 2 × 2 HCF of 24 and 16 = 2 × 2 × 2 = 8

Multiple choice

LCM of 1 and 2 is ______.

  1. 1

  2. 2

  3. 4

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

Multiples of 1 = 1, 2, 3, ... Multiples of 2 = 2, 4, ... LCM of 1 and 2 = 2

Multiple choice

HCF of 56 and 40 is _____.

  1. 6

  2. 8

  3. 10

  4. 19
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Factors of 56 = 2 × 2 × 2 × 7 Factors of 40 = 2 × 2 × 2 × 5 HCF of 56 and 40 = 2 × 2 × 2 = 8

Multiple choice

LCM of 3 and 4 is ______.

  1. 3

  2. 4

  3. 12

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

Multiples of 3 = 3, 6, 9, 12, 15 Multiples of 4 = 4, 8, 12, 16 LCM of 3 and 4 = 12