Question

3 1/2 ounces of cough syrup is used from a 9 1/4 ounce bottle how much is left

Answer 1

5 3/4 is left in the bottle

Answer 2

let's firstly convert the mixed fractions to improper fractions and then subtract.

$\bf \stackrel{mixed}{3\frac{1}{2}}\implies \cfrac{3\cdot 2+1}{2}\implies \stackrel{improper}{\cfrac{7}{2}}~\hfill \stackrel{mixed}{9\frac{1}{4}}\implies \cfrac{9\cdot 4+1}{4}\implies \stackrel{improper}{\cfrac{37}{4}} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{37}{4}-\cfrac{7}{2}\implies \stackrel{\textit{using the LCD of 4}}{\cfrac{(1)37~~-~~(2)7}{4}}\implies \cfrac{37-14}{4}\implies \cfrac{23}{4}\implies 5\frac{3}{4}$