Is 90 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 90 is composite or not first we have to find its factors.
Contents
Factors of 90:
- If we have taken numbers from 1, 2, 3…for checking factors of 90, we found that 90 has factors 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45 and 90. Hence, we must say that 90 is a composite number.
- Thus, 90 is the composite number.
- If we multiply 90 by 1, 2, 3 then we get the multiples of 90 which are 90, 180, and so on.
About the number 90:
- 90 has more than two factors which are 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45and 90 and hence it is the composite number.
- 90 is the even composite number and it is not the perfect square also.
- If we divide 90 by1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45 and 90 then we get remainder as zero. Hence, 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45 and 90 are the factors of 90.
Note:
- 90 is not the perfect square.
- Factors of 90: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45 and 90
- Prime factors of 90: 2, 3, 5
Conclusion:
- 90 is the composite number which has factors 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45 and 90.
- And hence, 90 is not the prime number.
Multiple Choice Questions:
1) 90 is a
a) even 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 90 are
a) 1
b) 2, 3, 5
c) Both a and b
d) 901
Ans: b) 2, 3, 5
3) 1 is the not prime factor of 90 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