Is 820 is a composite number or not ?
- As we already know that, the number having factors 1 and the number itself is the prime number.
- And numbers having more than these two factors are the composite numbers.
- To check whether the number 820 is composite or not first we have to find its factors.
Contents
Factors of 820:
- If we have taken numbers from 1, 2, 3…for checking factors of 820, we found that 820 has factors 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410 and 820. Hence, we must say that 820 is a composite number.
- Thus, 820 is the composite umber.
- If we multiply 820 by 1, 2, 3 then we get the multiples of 820 which are 820, 1640 and so on.
About the number 820:
- 820 has more than two factors which are 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410 and 820 and hence it is the composite number.
- 820 is the even composite number and it is not the perfect square also.
- If we divide 820 by 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410 and 820 then we get remainder as zero. Hence, 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410 and 820 are the factors of 820.
Note:
- 820 is not the perfect square.
- Factors of 820: 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410 and 820
- Prime factors of 820: 2, 5, 41
Conclusion:
- 820 is the composite number which has factors 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410 and 820
- And hence, 820 is not the prime number.
Multiple Choice Questions:
1) 820 is a
a) Odd number
b) Prime number
c) Composite number
d) Both b and c
Ans: c) composite number
2) The prime factors of a composite number 820 are
a) 1
b) 2, 5, 41
c) 1, 4, 10, 20, 82, 164, 205, 410 and 820
d) 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410 and 820
Ans: b) 2, 5, 41
3) 820 is the composite number because
a) It has factors 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410 and 820
b) It has only prime factors
c) Divisible by 2
d) Both a and b
Ans: a) It has factors 1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410 and 820