The motor ship sailed from one pier to another and returned back in 3.6 hours. Find the distance between the marinas

| July 25, 2021 | education

The motor ship sailed from one pier to another and returned back in 3.6 hours. Find the distance between the marinas if it sailed from one pier to another at a speed of 25 km / h, and back – at a speed of 20 km / h.

1) Let x km be the distance between the quays.

2) Then (x: 25) hours the motor ship sailed from one pier to another and (x: 20) hours it was on the way on the way back.

3) (х: 25 + х: 20) hours – so much time was spent by the motor ship for the entire journey, which, according to the condition of the problem, was 3.6 hours. Therefore, we write the equality:

x: 25 + x: 20 = 3.6.

4) Solve the equation:

20x + 25x = 3.6 * 25 * 20;

45x = 1800;

x = 1800: 45;

x = 40.

5) Having solved the equation, we find out that x = 40 km is the distance between the piers.

Answer: 40 km.



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