Question

Из двух го­ро­дов од­но­вре­мен­но нав­стре­чу друг другу от­пра­ви­лись два ве­ло­си­пе­ди­ста. Про­ехав не­ко­то­рую часть пути, пер­вый ве­ло­си­пе­дист сде­лал оста­нов­ку на 40 минут, а затем про­дол­жил дви­же­ние до встре­чи со вто­рым ве­ло­си­пе­ди­стом. Рас­сто­я­ние между го­ро­да­ми со­став­ля­ет 92 км, ско­рость пер­во­го ве­ло­си­пе­ди­ста равна 30 км/ч, ско­рость вто­ро­го — 12 км/ч. Опре­де­ли­те рас­сто­я­ние от го­ро­да, из ко­то­ро­го вы­ехал вто­рой ве­ло­си­пе­дист, до места встре­чи.

Answer 1

42 километра
решение очень простое

Answer 2

1) 30+12=42 (км/ч) - общая V;
2) 40 минут - это 2/3 часа; 12 * 2/3 = 8 (км) - проехал 2 велосипедист, пока 1 отдыхал;
3) 92-8=84 км - ехали оба велосипедиста одинаковое время;
4) 84:42=2 (ч) - это одинаковое время;
5) 12*2+8=32 (км) - проехал 2 велосипедист

Answer 3

Problem Analysis

We have two cyclists who start simultaneously from two different cities and meet each other after a certain distance. The first cyclist makes a 40-minute stop and then continues until they meet the second cyclist. The distance between the cities is 92 km, and the first cyclist's speed is 30 km/h, while the second cyclist's speed is 12 km/h. We need to determine the distance from the city where the second cyclist started to the meeting point.

Solution

To solve this problem, we can use the formula: distance = speed × time.

Let's denote the distance from the city where the second cyclist started to the meeting point as x km.

The first cyclist travels the entire distance between the cities (92 km) minus the distance x km. The time taken by the first cyclist is given by: time1 = (92 - x) / 30 hours.

The second cyclist travels the distance x km. The time taken by the second cyclist is given by: time2 = x / 12 hours.

Since the total time taken by both cyclists is equal to the time the first cyclist spent cycling before the meeting plus the 40-minute stop, we can write the equation:

time1 + time2 = (92 - x) / 30 + x / 12 = 40 / 60 hours.

To solve this equation, we can multiply both sides by the least common multiple (LCM) of 30 and 12, which is 60:

(92 - x) × 2 + 5x = 40.

Simplifying the equation:

184 - 2x + 5x = 40.

3x = 144.

x = 48.

Therefore, the distance from the city where the second cyclist started to the meeting point is 48 km.

Answer

The distance from the city where the second cyclist started to the meeting point is 48 km.