Is 720 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 720 is composite or not first we have to find its factors.
Factors of 720:
- If we have taken numbers from 1, 2, 3…for checking factors of 720, we found that 720 has factors 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360 and 720. Hence, we must say that 720 is a composite number.
- Thus, 720 is the composite umber.
- If we multiply 720 by 1, 2, 3 then we get the multiples of 720 which are 720, 1440 and so on.
About the number 720:
- 720 has more than two factors which are 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360 and 720 and hence it is the composite number.
- 720 is the even composite number and it is not the perfect square also.
- If we divide 720 by 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360 and 720 then we get remainder as zero. Hence, 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360 and 720 are the factors of 720.
Note:
- 720 is not the perfect square.
- Factors of 720: 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360 and 720
- Prime factors of 720: 2, 3, 5
Conclusion:
- 720 is the composite number which has factors 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360 and 720
- And hence, 720 is not the prime number.
Multiple Choice Questions:
1) 720 is a
a) perfect square number
b) Even number
c) Composite number
d) Both b and c
Ans: d) both b and c
2) The composite factors of a composite number 720 are
a) 4, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360,720
b) 2, 3, 5
c) 1, 4, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360 and 720
d) 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360 and 720
Ans: a) 4, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360, 720
3) 720 is the composite number because
a) It has factors 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360 and 720
b) More than two factors
c) Divisible by 2
d) Both a and b
Ans: d) both a and b