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Algebra Difficulty 1.5 Junior Find the answer Canada

Peter’s car uses $10.2$ L of
fuel per $100$ km. Mike’s hybrid car
uses $6.6$ L of fuel per $100$ km. Fuel costs $\$1.40$ per litre. If both Peter and Mike
drive $200$ km, how much less does
Mike spend on fuel?

Pick one

Solution

Peter’s car uses $10.2 $\text{}$
L} $of fuel per$ 100 $\text{}$
km} $, and thus uses$ $2\times10.2\text{}$ L}=20.4 $\text{}$ L}$ of
fuel per $200 \text{ km}$ . Fuel costs
$\$1.40/\text{L}$ and so Peter spends
$\$\$1.40/\text{L}\times20.4\text{}$
L}=\$28.56$ on fuel.

Mike’s car uses $6.6 \text{ L}$ of
fuel per $100 \text{ km}$ , and thus
uses $\$2\times6.6\text{ L}=13.2\text{}$
L} $of fuel per$ 200 $\text{}$
km} $. Fuel costs$ $\$1.40/\text{L}$ $and so Mike spends$ $\$1.40/\text{L}\times13.2\text{}$
L}=\$18.48$ on fuel.

Mike spends $\$28.56-\$18.48=\$10.08$
less than Peter on fuel.

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Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project.