You just have to pick a number that does not share a prime factor with it.
The easiest way to make a composite number with a prime is to square it.
a: 80,
80 has factors 2, 5. Pick another prime. 3, square it, 9
80 and 9 are coprime.
b:63
63 has prime factors 3, 7. Pick another prime, 5, square it, 25.
63 and 25 are coprime.
c: 135
135 has prime factors 3,5. Pick another prime. 7, square it, 49
135 and 49 are coprime.
,d: 88
88 has prime factors 2,11. Pick another prime. 3, square it, 9.
88 and 9 are coprime
e:52
52 has prime factors 2,13. Pick another prime, 3, square it, 9
52 and 9 are coprime.
f:81
81 has only the prime factor 3. Pick another prime 2, square it, 4,
81 and 4 are coprime
g:256
256 has only the prime factor 2. Pick another prime, 3, square it, 9,
256 and 9 are coprime.
h:216
216 has prime factors 2, 3. Pick another prime, 5, square it, 25,
216 and 25 are coprime.
i:294
294 has prime factor 2, 3, 7. Rick another prime, 5. Square it, 25.
294 and 25 are coprime.
j:1155
1155 has prime factors 3, 5, 7, 11. Pick another prime, 2. Square it, 4.
1155 and 4 are coprime.
Edwin
