JSS 1 Mathematics Flashcards: Finding the Highest Common Factor of Whole Numbers

Question 1

What is the highest common factor of 18 and 24?

Accepted Answer

6

Question 2

Find the HCF of 36 and 54.

Accepted Answer

18

Question 3

Find the HCF of 24, 40 and 56.

Accepted Answer

8

Question 4

Which number is a common factor of 42 and 70: 6, 7, 10 or 15?

Accepted Answer

7

Question 5

What is the greatest number that divides both 96 and 144 without a remainder?

Accepted Answer

48

Question 6

Using prime factors, what is the HCF of $60=2^2\times3\times5$ and $84=2^2\times3\times7$?

Accepted Answer

12

Question 7

What is the HCF of two coprime numbers such as 8 and 15?

Accepted Answer

1

Question 8

If 9 is a factor of 45, what is the HCF of 9 and 45?

Accepted Answer

9

Question 9

A teacher has 24 red pens and 36 blue pens. She makes the greatest possible number of identical packs with none left. How many packs can she make?

Accepted Answer

12

Question 10

For 24 red pens and 36 blue pens divided into 12 identical packs, how many pens of each colour are in one pack?

Accepted Answer

2 red and 3 blue

Question 11

A rectangular floor is 84 cm by 60 cm. What is the greatest side length of identical square tiles that fit exactly?

Accepted Answer

12 cm

Question 12

Simplify $42/56$ to its lowest terms.

Accepted Answer

3/4

Question 13

Which statement correctly distinguishes HCF from LCM?

Accepted Answer

HCF is the greatest shared factor; LCM is the least shared multiple.

Question 14

For positive integers 12 and 30, what is $\text{HCF}\times\text{LCM}$?

Accepted Answer

360

Question 15

What is the HCF of 17 and 34?

Accepted Answer

17

Question 16

Which is NOT a factor of 48: 6, 8, 12 or 14?

Accepted Answer

14

Question 17

The common factors of 20 and 30 are 1, 2, 5 and ____.

Accepted Answer

10

Question 18

Three ropes measuring 72 m, 90 m and 108 m are cut into longest equal pieces with no waste. What is each piece’s length?

Accepted Answer

18 m

Question 19

How many 18 m pieces are obtained altogether from ropes of 72 m, 90 m and 108 m?

Accepted Answer

15

Question 20

What is the HCF of 45 and 75?

Accepted Answer

15

Strong work.