Question 49543
55=x+x+1+x+2 or 3x=53 or x=53/3 or 17 2/3 thus 18+19+20=57 &
19+20+21=60 & 20+21+22=63 reject because these three =63 
thus there are two sets that meet the requirements  & they are (18,19,20)  & (19,20,21)