LCM and HCF

There are two loaf cakes. One is 35cm long and one is 21cm long. They want to cut the cake up and sell the slices, but all the slices must be equal. What is the largest slices that they can cut them into?

• HCF

• LCM

What is the LCM of 2, 4, 6?

• 6

• 12

• 4

• 2

There are two positive integers, a and b. Given that their HCF is 15. Which of the followings cannot be their LCM?

• 105

• 225

• 125

• 195

There are two positive integers, a and b. Which statement is always true?

• a x b = LCM(a,b) x HCF(a,b)

• a x b > LCM(a,b) x HCF(a,b)

• a x b < LCM(a,b) x HCF(a,b)

• (a x b)^2 = LCM(a,b) x HCF(a,b)

A common multiple of two integers is always a ____________ of their LCM.

• multiple

• factor

• (no answer)

What is the greatest common factor of 24 and 36?

• 2

• 3

• 12

• 24

What is the GCF of 4 and 12?

• 3

• 1

• 6

• 4

Given two different prime numbers, their HCF is:

• The smaller prime

• The larger prime

• 1

• Unknown, as we don't know what they are

Given two different prime numbers, their LCM is:

• The smaller prime

• The larger prime

• Unknown, as we don't know what they are

• Their product

• Their sum

There are two positive integers, a and b. Given that their LCM is 120. Which of the followings cannot be their HCF?

• 60

• 36

• 15

• 40