Question

A baker bought some flower. He used 2/5 of the flour to make bread and used the rest to make batches of muffins. If he used 16lb of flour making bread and 2/3 lb for each batch of muffins, how many batches of muffins did he make?

Answer 1

we know he used 2/5 of the flour for bread, we also know he used 16lbs for bread, that means, if the total amount is "x" lbs, then (2/5)x = 16.

$\bf \cfrac{2}{5}x=16\implies \cfrac{2x}{5}=16\implies x=\cfrac{5\cdot 16}{2}\implies x=40$

so, it was 40lbs total...now, he used 16lbs for bread, so the rest is for batches of muffins, namely 24lbs.

each batch of muffin uses 2/3 lb, so, how many times 2/3 goes into 24?

$\bf \cfrac{24}{\frac{2}{3}}\implies \cfrac{\frac{24}{1}}{\frac{2}{3}}\implies \cfrac{24}{1}\cdot \cfrac{3}{2}\implies \boxed{36}$