Is 390 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 390 is composite or not first we have to find its factors.
Contents
Factors of 390:
- If we have taken numbers from 1, 2, 3…for checking factors of 390, we found that 390 has factors 1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195 and 390. Hence, we must say that 390 is a composite number.
- Thus, 390 is the composite umber.
- If we multiply 390 by 1, 2, 3 then we get the multiples of 390 which are 390, 780 and so on.
About the number 390:
- 390 has more than two factors which are 1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195 and 390 and hence it is the composite number.
- 390 is the even composite number and it is not the perfect square also.
- If we divide 390 by 1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195 and 390 then we get remainder as zero. Hence, 1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195 and 390 are the factors of 390.
Note:
- 390 is not the perfect square.
- Factors of 390: 1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195 and 390
- Prime factors of 390: 2, 3, 5, 13
Conclusion:
- 390 is the composite number which has factors 1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195
- And hence, 390 is not the prime number.
Multiple Choice Questions:
1) 390 is a
a) Prime number
b) Odd number
c) Composite number
d) Both b and c
Ans: c) composite number
2) The non-prime factors of a composite number 390 are
a) 2
b) 2, 3, 5, 13
c) 1, 6, 10, 15, 26, 30, 39, 65, 78, 130, 195 and 390
d) 1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195 and 390
Ans: c) 1, 6, 10, 15, 26, 30, 39, 65, 78, 130, 195 and 390
3) 390 is the even composite number because
a) It has two factors
b) More than two factors
c) Divisible by 2
d) Both b and c
Ans: d) both b and c