Question: B. Solve the following problems completely.
1. Tsikoy can swim at a speed of 5 kph in calm water. The time it takes him to swim 4 kilometers upstream is the same as the time it takes to swim 16 kilometers downstream.
What is the speed of the current?
Solution:
d = rt
Distances Rate Time
Upstream
Downstream
Graph/table shape: a 4-column table with rows for Upstream and Downstream, positioned center.2. A boat travels 240 kilometers downstream in the same amount of time it takes to travel
160 kilometers upstream. The current's speed is 5 miles per hour. What is the boat's
speed in still water?
Solution:
d = rt
Distances | Rate | Time
Upstream | 160 kilometers | x - 5 |
Downstream | 240 kilometers | x + 5 |
table position_hint=bottom-center
User: answer this
1. **Problem:** Tsikoy swims at $5$ kph in calm water. The time to swim $4$ kilometers upstream is the same as the time to swim $16$ kilometers downstream. Find the speed of the current.
2. **Formula:** We use $d=rt$, so $t=\frac{d}{r}$.
3. **Set up the rates:**
- Upstream speed = $5-c$
- Downstream speed = $5+c$
where $c$ is the speed of the current.
4. **Write the time equation:**
$$\frac{4}{5-c}=\frac{16}{5+c}$$
5. **Cross-multiply and solve:**
$$4(5+c)=16(5-c)$$
$$20+4c=80-16c$$
$$20c=60$$
$$c=3$$
6. **Answer:** The speed of the current is $3$ kph.