The sum of three consecutive integers is three times the middle one: if we call the middle one [tex] x [/tex], the three numbers are
[tex] x-1,\ x,\ x+1 [/tex]
So, their sum is [tex] x-1+x+x+1 = 3x [/tex]
Which is three times the middle one.
So, if the sum of three consecutive intergers is 48, the middle one must be 48/3 = 16.
So, the three numbers are 15, 16 and 17