H. E. Dudeney, Amusements in Mathematics (1917) No. 9 · Puzzles · Money puzzles

The Two Aeroplanes

A man recently bought two aeroplanes, but afterwards found that they would not answer the purpose for which he wanted them. So he sold them for £600 each, making a loss of 20 per cent. on one machine and a profit of 20 per cent. on the other. Did he make a profit on the whole transaction, or a loss? And how much?

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H. E. Dudeney, Amusements in Mathematics (1917) · No. 9

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