Is 285 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 285 is composite or not first we have to find its factors.
Contents
Factors of 285:
- If we have taken numbers from 1, 2, 3…for checking factors of 285, we found that 285 has factors 1, 3, 5, 15, 19, 57, 95 and 285. Hence, we must say that 285 is a composite number.
- Thus, 285 is the composite number.
- If we multiply 285 by 1, 2, 3 then we get the multiples of 285 which are 285, 570, and so on.
285 is a Composite number or Prime number
About the number 285:
- 285 has more than two factors which are 1, 3, 5, 15, 19, 57, 95 and 285 and hence it is the composite number.
- 285 is the odd composite number and it is not the perfect square also.
- If we divide 285 by 1, 3, 5, 15, 19, 57, 95 and 285 then we get remainder as zero. Hence, 1, 3, 5, 15, 19, 57, 95 and 285 are the factors of 285.
Note:
- 285 is not the perfect square.
- Factors of 285: 1, 3, 5, 15, 19, 57, 95 and 285
- Prime factors of 285: 3, 5, 19
Conclusion:
- 285 is the composite number which has factors 1, 3, 5, 15, 19, 57, 95 and 285.
- And hence, 285 is not the prime number.
Multiple Choice Questions:
1) 285 is a
a) odd number
b) Prime number
c) Composite number
d) Both a and c
Ans: d) both a and c
2) The prime factors of a composite number 285 are
a) 1
b) 3, 5, 19
c) 1, 15, 57, 95 and 285
d) 1, 3, 5, 15, 19, 57, 95 and 285
Ans: b) 3, 5, 19
3) 285 is the odd composite number because
a) It has factors 1, 3, 5, 15, 19, 57, 95 and 285
b) It is divisible by 2
c) It is not divisible by 2
d) Both a and c
Ans: d) both a and c