Supergran walks from her chalet to the top of the mountain. She knows that if she walks at a speed of 6 mph she will arrive at 1pm, whereas if she leaves at the same time and walks at 10 mph, she will arrive at 11am.
At what speed should she walk if she wants to arrive at 12 noon?
Select one option, then click Submit.
7.5 \text{ mph}
7.75 \text{ mph}
8 \text{ mph}
Select an option, then submit.
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