If the total bill comes to $110.05, we know that we are going to have to take 15% of this for his tip.
So we convert 15% to a decimal by dividing by 100:
[tex] \frac{15}{100}=0.15 [/tex]
Then we multiply this by the amount of the bill:
[tex] 110.05*0.15=16.5075 [/tex]
So if we round this to the nearest cent, we get $16.51.
Therefore, Alberto's tip will be about $16.51.