we know that 240 = 2 × 2 × 2 × 3 × 5 and 315 = 3 × 3 × 5 × 7. Use the prime factors to find the HCF of 240 and 315.
15
15
What are the values of A and B in this factor tree?
A=120
B=10
15
2100 = 2 × 2 × 3 × 5 × 5 × 7 and 1500 = 2 × 2 × 3 × 5 × 5 × 5.
Use the prime factors of 2100 to find the HCF of 2100 and 1500.
300
15
What is the common prime factor of 6 and 21?
3
10
2100 = 2 × 2 × 3 × 5 × 5 × 7
Use the prime factors of 2100 to find the HCF of 700 and 2100.
700
15
Find the LCM of 35 and 80, using these factor trees.
560
20
Find the LCM and HCF of 1800 and 900.
LCM = 1800
HCF = 900
15
What is the smallest number with three different prime factors?
30
20
The HCF of two different numbers is 45. One of these numbers is 45.
What can be said about the two numbers?
a) 45 is smaller than the other number.
b) Both numbers have 45 as a multiple.
c) Both numbers have 45 as a factor.
