6.8
6
The least common multiple of the numbers 23, 57 and 11 is 14,421
How about: 23+34 = 57
Out of that list, only 57 is composite.
27, 57 and 77 are composite.
Of those odd numbers, only 57 is composite.
23 is smaller than 57 ... 57-23=34
57 + 23 = 80
There are infinitely many answers. The following are some examples: 1+2+54 = 57 or 1+100-44 = 57 or 1*2*28.5 = 57 or 1*114/2 = 57
34 + 23 = 57
75.
The prime numbers from 1 to 57 are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, and 53.