# The boat, moving along the river, in 7 hours covers the same distance that it covered in 8 hours against the current.

**The boat, moving along the river, in 7 hours covers the same distance that it covered in 8 hours against the current. What is the speed of the river flow if the boat’s own speed is 30 km / h?**

1. Let’s say the speed of the river is x km per hour.

2. Then the speed of the boat along the river is (30 + x) km per hour.

3. The speed of the boat against the flow of the river is equal to (30 – x) km per hour.

4. The distance that the boat traveled along the river in 7 hours is 7 * (30 + x) km.

5. The distance that the boat traveled against the river flow in 8 hours is 8 * (30 – x) km.

6. Let’s make an equation and find out the speed of the river, if in both cases the path is the same.

7 * (30 + x) = 8 * (30 – x);

210 + 7x = 240 – 8x;

7x + 8x = 240 – 210;

15x = 30;

x = 30/15;

x = 2 km per hour.

Answer: The speed of the current is 2 km per hour.