Factors and Multiples Question 1

What is the least common multiple of 20, 30, and 130 ?

60

78

180

780

78{,}000

Approach 1

We should check if each answer choice is a multiple of each.

$60$ , $78$ , and $180$ are not multiples of $130$ .

$780$ is a multiple of all three since it is divisible by all three numbers.

Approach 2

20 = 10\cdot 2

30 = 10 \cdot 3

130 = 10\cdot 13

Therefore, the least common multiple will have all the common factors:

10 \cdot 2\cdot 3\cdot 13 = \boxed{780}