Question

Катер в первый час плыл со скоростью 18км/ч.Во второй час уменьшил скорость на 15% , а в третий час последнюю скорость увеличил на 20%.Какова скорость катера в третий час ?

Answer 1

18*15/100=2,7 км/ч на столько уменьшил
18-2,7=15,3 км/ч - скорость второго часа
15,3*20/100=3,06 км/ч на столько увеличил
15,3+3,06=18,36 км/ч скорость третьего часа

Answer 2

Calculation of the Speed of the Boat in the Third Hour

To calculate the speed of the boat in the third hour, we need to consider the changes in speed that occurred in the first and second hours.

In the first hour, the boat was traveling at a speed of 18 km/h.

In the second hour, the boat reduced its speed by 15%. To calculate the reduced speed, we can multiply the original speed by (100% - 15%) or 0.85. Therefore, the speed in the second hour was 18 km/h * 0.85 = 15.3 km/h.

In the third hour, the boat increased its speed by 20%. To calculate the increased speed, we can multiply the reduced speed from the second hour by (100% + 20%) or 1.20. Therefore, the speed in the third hour was 15.3 km/h * 1.20 = 18.36 km/h.

The speed of the boat in the third hour was 18.36 km/h.

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