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Macedonian Mathematical Competitions

Algebra Difficulty 3.8 AMC 10/12 Find the answer North Macedonia

During three hours a driver with a car has driven $180\,km$ . During the first hour he has driven $0.375$ from the whole distance and during the second hour he has driven $0.9$ from the distance that he had driven during the first hour. What distance has the driver driven during the third hour?

Your answer

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

Solution

The third hour the driver has driven $180 - 0.375 \cdot 180 - 0.9 \cdot 0.375 \cdot 180 = 51.75\,km = 51\,km\ 75m$ .

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