Question

Write any 5 numbers which are divisible by 2,5 and 10.

Answer 1

Hint-In this question, we use the theory of LCM (Least Common Multiple) for finding the numbers which are divisible by 2,5 and 10. As we know, in arithmetic, the LCM is the smallest or least positive integer that is divisible by both a and b. So, in this question we need to calculate the LCM of 2,5 and 10.

Complete step-by-step answer:
For example, let us take two positive integers 4 and 6. Multiples of 4 are: 4,8,12,16,20,24… Multiples of 6 are: 6,12,18,24…. The common multiples for 4 and 6 are 12,24,36,48…and so on.
Arrange the group of numbers in the horizontal form with space or comma separated format
2, 5 and 10 (LCM by Division Method).

LCM of 2, 5 and 10 = 2X5
                                  = 10
Since, we get LCM of 2, 5 and 10 is 10.
So, if a number is divisible by 10
Then it will be divisible by 2,5,10.
Therefore, any number which is multiple of 10 or which is divisible by 10. We say it will be divisible by 2,5,10.
Like- 10, 20, 30, 40, 50, 60, 70, 80 etc.
Thus, 10, 20, 30, 40, 50 are 5 numbers which are divisible by 2,5 and 10.

Note- To calculate the LCM of two numbers a and b. We will also use another method, which is called the Prime Factorisation method to calculate LCM of two numbers.
For example, List the prime factors of each number first as shown-
60 = 2 × 2 x 3 × 5
45 = 3 × 3 × 5