Which of the following statements are true?
I. The mean price of a mixture lies between the lowest and highest prices mixed.
II. When equal quantities are mixed, the mean price is the simple average of the prices.
III. When equal amounts of money are spent on each kind, the mean price is the simple average of the prices.
IV. Adding water to milk lowers the cost of a litre of the mixture.

All four: I, II, III and IVCorrect answerYour answerI and II onlyCorrect answerYour answerI and IV onlyCorrect answerYour answerI, II and IV onlyCorrect answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer D

Correct answer: D

I: a weighted mean never leaves the range of what is averaged. II: equal weights give the simple average. IV: water adds litres but no cost.
III is false: equal money buys more of the cheaper kind, so the mean falls below the simple average.

Concept: Facts about mean prices
Typical timeTypical: 120 s
Your timeYours: —

The rule this testsThe mean price of a mixture

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Ten questions from Alligation & Mixtures, at your own pace.

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