Is 3840 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 3840 is composite or not first we have to find its factors.
Factors of 3840:
- If we have taken numbers from 1, 2, 3…for checking factors of 3840, we found that 3840 has factors 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920 and 3840. Hence, we must say that 3840 is a composite number.
- Thus, 3840 is the composite number.
- If we multiply 3840 by 1, 2, 3 then we get the multiples of 3840 which are 3840, 7680 and so on.
About the number 3840:
- 3840 has more than two factors which are 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920 and 3840 and hence it is the composite number.
- 3840 is the even composite number and it is not the perfect square also.
- If we divide 3840 by, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920 and 3840 then we get remainder as zero. Hence, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920 and 3840 are the factors of 3840.
Note:
- 3840 is not the perfect square.
- Factors of 3840: 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920 and 3840
- Prime factors of 3840: 2, 3, 5
Conclusion:
- 3840 is the composite number which has factors, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920 and 3840
- And hence, 3840 is not the prime number.
Multiple Choice Questions:
1) 3840 is a
a) Prime 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 3840 are
a) 3840
b) 2, 3, 5
c) 4, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920 and 3840
d) 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920 and 3840
Ans: c) 4, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920 and 3840
3) 3840 is composite number because
a) It has factors 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 128, 160, 192, 240, 256, 320, 384, 480, 640, 768, 960, 1280, 1920 and 3840
b) It has more than two factors
c) Divisible by 2
d) Both a and b
Ans: d) both a and b