A factory buys 25 tonnes of flour. $17\frac{1}{2}$ tonnes of the flour is used to make scones. $\frac{1}{5}$ of the scones are cheese scones.
a) What fraction of the total amount of flour is used to make cheese scones?
$17\frac{1}{2}$ * $\frac{1}{5}$ but I don't know how to approach this question.
b) What percentage of the flour is used to make cheese scones?
You already said $17\frac{1}{2}*\frac{1}{5} = \frac{7}{2}$ - this is the amount of flour they used to make cheese scones. So, what is the fraction of the flour they used to make cheese scones? It's just this divided by the total amount of flour: $\left(\frac{7}{2}\right)/25 =\frac{7}{50}$ tonnes.
We can convert this to a percentage for part $b)$ as $\frac{7}{50} = \frac{14}{100} = 14\%$.
(a) A fifth of $17.5$ tonnes is used to make cheese scones, from the problem. It follows that the fraction of the total used for cheese scones is $$\frac{\frac{1}{5}×17.5}{25}.$$ Can you simplify this?
(b) To express a fraction as a percentage means to write it as some multiple of $1/100,$ which is often shortened as $\%.$ You can always do this by multiplying the fraction by $100/100=100\%,$ which doesn't change anything. Thus, multiplying the above fraction by $100\%$ gives $$\frac{\frac{1}{5}×17.5}{25}×100\%,$$ which you can also simplify.
