so since Mrs Jackson used 2/15 of 7/8, the amount she used is simply their product.
[tex]\bf \stackrel{\textit{how much is }\frac{2}{15}\textit{ of }\frac{7}{8}?}{\cfrac{7}{8}\cdot \cfrac{2}{15}}\implies \cfrac{7}{15}\cdot \cfrac{2}{8}\implies \cfrac{7}{15}\cdot \cfrac{1}{4}\implies \cfrac{7}{60}[/tex]
