Given the information on the proble, we have to substract 2/3 cups from the 9/10 cups that the jar contains. We can use the following general rule for the substraction of fractions:
[tex]\begin{gathered} \frac{a}{b}-\frac{c}{d}=\frac{a\cdot d-b\cdot c}{b\cdot d} \\ b,d\ne0 \end{gathered}[/tex]then, in this case, we have the following:
[tex]\frac{9}{10}-\frac{2}{3}=\frac{9\cdot3-10\cdot2}{10\cdot3}=\frac{27-20}{30}=\frac{7}{30}[/tex]therefore, there are 7/30 cups of honey left in the jar
