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Problem 797

AMC 10/12, early questions

Geometry Difficulty 3.6 Find the answer Macedonian Mathematical Competitions · North Macedonia

One square meter of tin costs 35 denars. How much money is needed to buy tin for 50 opened pots (without roof) with polyhedral shape with dimensions: length 20 cm, width 2 dm and height 4 dm?

Your answer

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

Official solution

For one such pot we need $2 \cdot 2 + 4 \cdot 2 \cdot 4 = 36\,dm^2$ of tin. For 50 we need $50 \cdot 36 = 1800\,dm^2 = 18m^2$ of tin. So we need $18 \cdot 35 = 630$ denars.

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