Input data
Last week
Coffee for $12.80
Current week
15 % Discount
How cost 2 3/4 pounds
Procedure
The total cost of coffee would be
[tex]2\frac{3}{4}\cdot12.80=35.2[/tex]Now let's apply the discount
d = discount
[tex]\begin{gathered} d=35.2\cdot15\text{ \%} \\ d=5.28 \end{gathered}[/tex]The final cost would be
[tex]\begin{gathered} C=35.2-5.28 \\ C=29.92 \end{gathered}[/tex]The tatoal cost would be $ 29.92