Question

Велосепедист отправился догонять пешехода,когда расстояние между ними было 21км.Скорость велосипедиста 12км/ч,скорость пешехода 5 км/ч Через сколько часов велосипедист догонит пешехода?

Answer 1

12-5=7;21:7=3.через 3 часа догонит

Answer 2

Problem Analysis

To solve this problem, we need to determine the time it takes for the cyclist to catch up to the pedestrian. We are given the initial distance between them, the speed of the cyclist, and the speed of the pedestrian.

Solution

Let's calculate the time it takes for the cyclist to catch up to the pedestrian.

We can use the formula: time = distance / speed.

The distance between the cyclist and the pedestrian is initially 21 km. The speed of the cyclist is 12 km/h, and the speed of the pedestrian is 5 km/h.

Substituting these values into the formula, we get:

time = 21 km / (12 km/h - 5 km/h)

Simplifying the expression inside the parentheses, we have:

time = 21 km / 7 km/h

Calculating the division, we find:

time = 3 hours

Therefore, the cyclist will catch up to the pedestrian in 3 hours.

Answer

The cyclist will catch up to the pedestrian in 3 hours.

Source:

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