Question

из пунктов А и B, расстояние между которыми 21 км, отправляются в путь одновременно пешеход из B и вдогонку ему велосипедист из A.скорость пешехода 5км/ч., велосипедиста 12км/ч.На сколько километров уменьшится расстояние между ними через 3ч.​

Answer 1

Ответ:

12-5=7

7×3=21

Ответ:21 км

Answer 2

Problem Analysis

We are given two points, A and B, which are 21 km apart. A pedestrian starts walking from point B at a speed of 5 km/h, and a cyclist starts chasing the pedestrian from point A at a speed of 12 km/h. We need to determine how much the distance between them will decrease after 3 hours.

Solution

To solve this problem, we can calculate the distance covered by the pedestrian and the cyclist after 3 hours and then subtract this distance from the initial distance of 21 km.

Calculation

The distance covered by the pedestrian after 3 hours can be calculated using the formula:

Distance = Speed x Time

For the pedestrian: Distance = 5 km/h x 3 h = 15 km

The distance covered by the cyclist after 3 hours can also be calculated using the same formula:

For the cyclist: Distance = 12 km/h x 3