# Number - Lowest Common Multiples

a - answer    s - solution    v - video

## Question 1

List the first $5$ multiples of each number and find their lowest common multiple

a) $2,3$a s v
b) $3,4$a s v
c) $6,8$a s v
d) $4,8$a s v
e) $6,10$a s v
f) $8,12$a s v
g) $15,20$a s v
h) $30,50$a s v

## Question 2

List the first $6$ multiples of each number and find their lowest common multiple

a) $2,3,4$a s v
b) $4,6,8$a s v
c) $5,6,10$a s v
d) $6,9,12$a s v
e) $5,8,20$a s v
f) $10,12,15$a s v

## Question 3

List the first $15$ multiples of each number and find their lowest common multiple

a) $2,3,5$a s v
b) $2,3,7$a s v
c) $4,7,9$a s v
d) $4,5,6$a s v
e) $3,4,10$a s v

## Question 4

List the first $10$ multiples of each number and find their lowest common multiple

a) $9,15$a s v
b) $12,14$a s v
c) $16,24$a s v
d) $12,21$a s v
e) $14,16$a s v
f) $15,80$a s v
g) $24,28$a s v
h) $42,60$a s v

## Question 5

By finding prime factors, find the lowest common multiple of:

a) $14,15$a s v
b) $15,22$a s v
c) $20,44$a s v
d) $21,35$a s v
e) $28,30$a s v
f) $14,25$a s v
g) $15,32$a s v
h) $12,52$a s v

## Question 6

By finding prime factors, find the lowest common multiple of:

a) $12,15,16$a s v
b) $15,16,32$a s v
c) $20,24,32$a s v
d) $15,20,25$a s v
e) $28,42,63$a s v
f) $24,32,40$a s v
g) $24,30,54$a s v
h) $39,65,78$a s v

## Question 7

By finding prime factors, find the lowest common multiple of:

a) $42,68$a s v
b) $92,100$a s v
c) $45,66$a s v
d) $85,98$a s v
e) $36,55$a s v
f) $44,105$a s v
g) $46,87$a s v
h) $67,91$a s v

## Question 8

By finding prime factors, find the lowest common multiple of:

a) $20,35,40$a s v
b) $18,25,38$a s v
c) $52,68,78$a s v
d) $36,64,78$a s v
e) $35,52,98$a s v
f) $104,105,112$a s v
g) $85,130,200$a s v
h) $17,62,99$a s v

## Question 9

a) Consider the following list of prime factors:

$30=2\times3\times5$
$42=2\times3\times7$

Find the Lowest Common Multiple of $30$ and $42$a s v

b) Consider the following list of prime factors:

$70=2\times5\times7$
$105=3\times5\times7$

Find the Lowest Common Multiple of $70$ and $105$a s v

c) Consider the following list of prime factors:

$12=2\times2\times3$
$66=2\times3\times11$

Find the Lowest Common Multiple of $12$ and $66$a s v

d) Consider the following list of prime factors:

$90=2\times3\times3\times5$
$56=2\times2\times2\times7$

Find the Lowest Common Multiple of $90$ and $56$a s v

## Question 10

Find what is missing from the boxes

a) Consider the following list of prime factors:

$30=2\times3\times5$
$105=3\times5\times7$

The Lowest Common Multiple of $30$ and $105=2\times\square\times5\times7$a s v

b) Consider the following list of prime factors:

$20=2\times2\times5$
$18=2\times3\times3$

The Lowest Common Multiple of $20$ and $18$ is $2\times2\times\square\times\square\times\square$a s v

c) Consider the following list of prime factors:

$56=2^3\times7$
$70=2\times5\times7$

The Lowest Common Multiple of $56$ and $70$ is $\square\times\square\times\square\times5\times7$a s v

d) Consider the following list of prime factors:

$495=3^2\times5\times11$
$825=3\times5^2\times11$

The Lowest Common Multiple of $495$ and $825$ is $3^2\times\square^2\times\square$a s v