1. prime numbers from 1 to 20

Solution:

Number	Factors	Prime or Composite?
1	1	neither Prime nor Composite
2	1,2	Prime
3	1,3	Prime
4	1,2,4	Composite
5	1,5	Prime
6	1,2,3,6	Composite
7	1,7	Prime
8	1,2,4,8	Composite
9	1,3,9	Composite
10	1,2,5,10	Composite
11	1,11	Prime
12	1,2,3,4,6,12	Composite
13	1,13	Prime
14	1,2,7,14	Composite
15	1,3,5,15	Composite
16	1,2,4,8,16	Composite
17	1,17	Prime
18	1,2,3,6,9,18	Composite
19	1,19	Prime
20	1,2,4,5,10,20	Composite

Prime numbers : between 1 and 20
2, 3, 5, 7, 11, 13, 17, 19

There are 8 prime numbers between 1 and 20

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2. composite numbers from 50 to 60

Solution:

Number	Factors	Prime or Composite?
50	1,2,5,10,25,50	Composite
51	1,3,17,51	Composite
52	1,2,4,13,26,52	Composite
53	1,53	Prime
54	1,2,3,6,9,18,27,54	Composite
55	1,5,11,55	Composite
56	1,2,4,7,8,14,28,56	Composite
57	1,3,19,57	Composite
58	1,2,29,58	Composite
59	1,59	Prime
60	1,2,3,4,5,6,10,12,15,20,30,60	Composite

Composite numbers : between 50 and 60
50, 51, 52, 54, 55, 56, 57, 58, 60

There are 9 composite numbers between 50 and 60

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3. prime numbers from 1 to 100

Solution:
Prime numbers : between 1 and 100
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97

There are 25 prime numbers between 1 and 100

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4. prime numbers from 1 to 1000

Solution:
Prime numbers : between 1 and 1000
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997

There are 168 prime numbers between 1 and 1000

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