Maths Olympiad Prep

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, 2023

Algebra Difficulty 1.4 Junior Find the answer Canada

The grocery receipt shows the cost of three items before tax is
added.

When a 5%5\% tax is added to the
cost of the items, what is the total cost for the three items?

Pick one

Solution

Before adding tax, the combined cost of the three items is $4.20+$7.60+$3.20=$15.00\$4.20+\$7.60+\$3.20=\$15.00.

The 5% tax on 15.00is15.00 is 0.05×0.05\times
\$15.00=\$0.75$, and so the total cost of the three items, after
tax is added, is $15.00+$0.75=$15.75\$15.00+\$0.75=\$15.75.

Note that we could have calculated the 5% tax on each individual item,
however doing so is less efficient than calculating tax on the $15.00
total.

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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.