It is required that you find the unit price in cents per diaper.
To do this, convert the prices in dollars to cents by multiplying by 100.
[tex]\begin{gathered} \$11.99=11.99\times100\text{ cents} \\ =1199¢ \end{gathered}[/tex][tex]\begin{gathered} \$11.49=11.49\times100\text{ cents} \\ =1149¢ \end{gathered}[/tex]Next, divide the respective prices in cents by the corresponding number of diapers:
For brand A:
[tex]\frac{1199}{36}\approx33.3¢\text{ per diaper}[/tex]For brand B:
[tex]\frac{1149}{50}=22.98\approx23.0¢\text{ per diaper}[/tex]Next, notice that Brand B has a lower unit price. Hence, it is the better buy.
Brand B is the better buy,