Is 85 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 85 is composite or not first we have to find its factors.
Contents
Factors of 85:
- If we have taken numbers from 1, 2, 3…for checking factors of 85, we found that 85 has factors 1, 5, 17 and 85. Hence, we must say that 85 is a composite number.
- Thus, 85 is the composite number.
- If we multiply 85 by 1, 2, 3 then we get the multiples of 85 which are 85, 170, and so on.
About the number 85:
- 85 has more than two factors which are 1,5, 17and 85 and hence it is the composite number.
- 85 is the odd composite number and it is not the perfect square also.
- If we divide 85 by 1, 5, 17 and 85 then we get remainder as zero. Hence, 1, 5, 17 and 85 are the factors of 85.
Note:
- 85 is not the perfect square.
- Factors of 85: 1, 5, 17 and 85
- Prime factors of 85: 5, 17
Conclusion:
- 85 is the composite number which has factors 1, 5, 17and 85.
- And hence, 85 is not the prime number.
Multiple Choice Questions:
1) 85 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 85 are
a) 1
b) 5, 17
c) Both a and b
d) 851
Ans: b)5, 17
3) 1 is the not prime factor of 85 because
a) It is the prime number
b) 1 is neither prime nor composite number
c) Both a and b
d) Given statement is false
Ans: b) 1 is neither prime nor composite number