Question

The prime factor trees for 42 and 455

are shown below.
Use the prime factor trees to find the
lowest common multiple (LCM) of
42 and 455.
2
42
3
21
7
5
455
7
91
13

Answer 1

42 = 2 × 3 × 7

455 = 5 × 7 × 13

LCM of 42 and 455 = 2 × 3 × 5 × 7 × 13

= 2,730