As given by the question
There are given that the the regular price is $15.99
Now,
If 40% off for today, then the price will be:
[tex]\begin{gathered} 15.99\times\frac{40}{100}=15.99\times\frac{4}{10} \\ =6.396 \end{gathered}[/tex]Then,
[tex]15.99-6.396=9.594[/tex]Hence, the price of pizza for toda is $9.59.