Is 1800 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 1800 is composite or not first we have to find its factors.
Factors of 1800:
- If we have taken numbers from 1, 2, 3…for checking factors of 1800, we found that 1800 has factors 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800. Hence, we must say that 1800 is a composite number.
- Thus, 1800 is the composite number.
- If we multiply 1800 by 1, 2, 3 then we get the multiples of 1800 which are 1800, 3600 and so on.
About the number 1800:
- 1800 has more than two factors which are 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800 and hence it is the composite number.
- 1800 is the even composite number and it is not the perfect square also.
- If we divide 1800 by, 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800 then we get remainder as zero. Hence, 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800 are the factors of 1800.
Note:
- 1800 is not the perfect square.
- Factors of 1800: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800
- Prime factors of 1800: 2, 3, 5
Conclusion:
- 1800 is the composite number which has factors 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800
- And hence, 1800 is not the prime number.
Multiple Choice Questions:
1) 1800 is a
a) Prime number
b) Odd number
c) Composite number
d) Both a and c
Ans: c) composite number
2) The non-prime factors of a composite number 1800 are
a) 1800
b) 2, 3, 5
c) 1, 4, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800
d) 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800
Ans: c) 1, 4, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800
3) 1800 is composite number because
a) It has factors 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800
b) It has only two factors
c) Divisible by 2
d) Both a and c
Ans: a) it has factors 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 25, 30, 36, 40, 45, 50, 60, 72, 75, 90, 100, 120, 150, 180, 200, 225, 300, 360, 450. 600, 900 and 1800