The speed of the river is 2 km / h. The motor boat moved along the river for 4 hours, and against 2 hours

The speed of the river is 2 km / h. The motor boat moved along the river for 4 hours, and against 2 hours. It turned out that it went 28 km more downstream than against the current. Find your own boat speed

1. To solve the problem, we use the formula
S = v * t, where S is distance, v is speed, and t is time. Let the boat’s own speed be equal to x, we express its path along the current and against the current:
S downstream = (2 + x) * 4,
S upstream = (x – 2) * 2.
2. since the path along the stream is 28 km longer than the path against the stream, we compose the equation, we find x:
(2 + x) * 4 = 28 + (x – 2) * 2,
8 + 4x = 28 + 2x – 4,
4x – 2x = 24 – 8,
2x = 16,
x = 16/2,
x = 8 km / h.
Answer: the motor boat’s own speed is 8 km / h.