Part A: Estimating the difference
Looking at the fraction part, we have the following
[tex]\begin{gathered} 2\frac{2}{5} \\ 1\frac{8}{10}\Longrightarrow1\frac{4}{5} \end{gathered}[/tex]
If we add 1/5 more, then Carmen's and Jorge's bottle will be the same in capacity.
If we add 1/5 to 2/5, the result would be 3/5, and 3 is more than half of 5, this is why Jorge's estimate is reasonable.
Part B: Solving for the actual difference
Convert both into improper fractions
[tex]\begin{gathered} \text{Jorge's Bottle}\colon2\frac{2}{5}\Longrightarrow\frac{12}{5} \\ \text{Carmen's Bottle}\colon1\frac{4}{5}\Longrightarrow\frac{9}{5} \\ \\ \text{Subtract both} \\ \frac{12}{5}-\frac{9}{5}=\frac{3}{5} \\ \\ \text{Therefore},\text{ the actual difference is } \\ \frac{3}{5} \end{gathered}[/tex]
