The boat traveled along the river in 3 hours the same distance as it travels in 3 hours and 36 minutes against the current. If the speed of the river is 3 km / h, then the boat’s own speed is …
1. We translate minutes into hours:
3 hours 36 minutes = 3 and 36/60 hours = 3.6 hours.
2. Take the speed of the boat in still water (own speed) as x (km / h).
3. Down the river the boat sailed at a speed of (x + 3 km / h, in the opposite direction it sailed at a speed of (x – 3) km / h.
4. Considering that the boat sailed down the river, as many kilometers as in the opposite direction, we compose the equation:
3 (x + 3) = 3.6 (x – 3);
3x + 9 = 3.6x – 10.8;
0.6x = 19.8;
x = 33 km / h.
Answer: the speed of the boat in still water is 33 km / h.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.