Question

What is the lowest common multiple of 16 and 20?

Answer 1

Hint: We are given a question to find the lowest common multiple of the given numbers 16 and 20. Lowest common multiple refers to the number which is first and the lowest common multiple of both the numbers taken under consideration. So, in order to find the lowest common multiple of 16 and 20, we will first write the factors of each of the numbers given to us, then we will take out terms which are not common in both the numbers. If a term is common in both the numbers, then we take that term only once. We will then multiply the segregated terms and hence, we will have the LCM of the given numbers.

Complete step by step answer:
According to the given question, we have to find the lowest common multiple of the given numbers 16 and 20.
LCM or Lowest Common Multiple refers to the smallest number which is multiple of numbers taken under consideration.
So, the numbers we have is, 16 and 20.
We will begin by writing the factors of both the numbers given to us, we have,
\[16=2\times 2\times 2\times 2\]
\[20=2\times 2\times 5\]
We can see that in both 16 and 20, the factor 2 is repeated twice, that is, two pairs but we will take only one pair. Then we will take out the remaining two 2’s from 16 and a 5 from the number 20. So, we get,
\[LCM(16,20)=2\times 2\times 2\times 2\times 5=80\]
Therefore, \[LCM(16,20)=80\]

Note: While finding the LCM, firstly take out those terms which are not common in any of the number’s factors under consideration. Then, proceed onto the common factors, in which you take the factor once if it is common for all numbers under consideration and two, if it appears twice in every number’s factors and so on.