Unit price questions, comparing two offers per unit
To compare two offers of different sizes, divide each price by what it buys to get a price per unit, then compare those unit prices. After you submit, each one shows the working and names the wrong turn behind every other option.
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One question of this type, worked in full
Work it out on paper, then open Check your answer to see the full solution.
Pack A holds 36 filters and costs 18 euros. Pack B holds 40 filters and costs 30 euros. How many cents less does one filter cost in Pack A than in Pack B?
Check your answer
- Pack A costs 18 euros, which is 1,800 cents, for 36 filters, so one filter costs 1,800 ÷ 36 = 50 cents.
- Pack B costs 30 euros, which is 3,000 cents, for 40 filters, so one filter costs 3,000 ÷ 40 = 75 cents.
- The gap between the two unit prices is 75 − 50 = 25 cents, so one filter costs 25 cents less in Pack A.
Answer: 25 cents. Testonome practice pace: 75 seconds for a question like this.
Four ways this question type goes wrong
Each question offers four wrong answers beside the right one, drawn from a longer list of mistakes. These four are among them, and the review names the one you took.
Pack prices compared
Subtracting one pack price from the other, which compares what the packs cost and ignores how many filters each one holds.
Cheaper rate only
Stopping once Pack A's price per filter is worked out, so the first rate is stated and never compared with the second.
Dearer rate only
Giving Pack B's price per filter as the answer, so one pack's rate is reported where the gap between the two was asked for.
Filters per euro
Dividing the filters by the euros instead of the euros by the filters, so both rates are the wrong way up before they are compared.
What the review gives you after you submit
You get the working for every question, the answer you chose beside the right one, and the reason the option you picked is wrong. Nothing is sent anywhere while you work.