157,444 views
25 votes
25 votes
Solve using a proportion.

Blake earns $60 a week mowing lawns. He
saves 30% of what he makes per week and
spends the rest on food. How much does
Blake spend each week on food?
word

User Chad M
by
3.4k points

2 Answers

13 votes
13 votes

well, we know that he makes $60 weekly, that'd be the 100%, we also know that he saves 30% of that and the rest, well, 100% - 30% = 70%, so 70% he spends it on food.

if we take 60 to be the 100%, what is 70% of it?


\begin{array}{ccll} amount&\%\\ \cline{1-2} 60 & 100\\ x& 70 \end{array} \implies \cfrac{60}{x}=\cfrac{100}{70}\implies \cfrac{60}{x}=\cfrac{10}{7} \\\\\\ 420=10x\implies \cfrac{420}{10}=x\implies 42=x

User Peter Wateber
by
2.9k points
7 votes
7 votes
Blake will end up spending $20 a week on food
User Benjamin Jones
by
2.7k points