Question

ВЕЛОСИПЕДИСТ ЗА 6 ЧАСОВ ПРОЕХАЛ 72 км.Скорость мотоциклиста на 15км/ч больше скорости велосипедиста.За сколько часов мотоциклист проедет 81 км.

Answer 1

1) 72:6=12(км)-скорость велосепедиста;
2)12+15=27(км)-скорость мотоциклиста;
3)81:27=3(ч)
Ответ:Мотоциклист проедет 81 км за 3 часа

Answer 2

Problem Analysis

We are given that a cyclist traveled 72 km in 6 hours, and the speed of a motorcyclist is 15 km/h faster than the speed of the cyclist. We need to determine how many hours it will take for the motorcyclist to travel 81 km.

Solution

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

Let's denote the speed of the cyclist as x km/h. The speed of the motorcyclist will then be x + 15 km/h.

We know that the cyclist traveled 72 km in 6 hours, so we can set up the equation:

72 = x × 6.

Solving for x, we find:

x = 72 / 6 = 12 km/h.

Therefore, the speed of the cyclist is 12 km/h, and the speed of the motorcyclist is 12 + 15 = 27 km/h.

Now, we can use the formula distance = speed × time to find the time it will take for the motorcyclist to travel 81 km:

81 = 27 × time.

Solving for time, we find:

time = 81 / 27 = 3 hours.

Therefore, it will take the motorcyclist 3 hours to travel 81 km.

Answer

The motorcyclist will travel 81 km in 3 hours.

Verification

Let's verify the solution using the given information.

The cyclist traveled 72 km in 6 hours, which means their speed was 12 km/h. The motorcyclist's speed is 15 km/h faster, so their speed is 27 km/h.

Using the formula distance = speed × time, we can calculate the time it will take for the motorcyclist to travel 81 km:

81 = 27 × time.

Solving for time, we find:

time = 81 / 27 = 3 hours.

Therefore, the solution is verified.

Conclusion

The motorcyclist will travel 81 km in 3 hours, assuming their speed is 15 km/h faster than the speed of the cyclist.