--
To find the speed of the stream, we need to use the given information and some basic calculations. Here’s how we can solve this step-by-step:
1. **Speed of the boat in still water:** 13 km/hr
2. **Distance traveled downstream:** 84.7 km
3. **Time taken to travel downstream:** 5.5 hours
### Step 1: Find the downstream speed
The formula for speed is:
\[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \]
Using the given values:
\[ \text{Downstream speed} = \frac{84.7 \text{ km}}{5.5 \text{ hours}} \]
Let's calculate this:
\[ \text{Downstream speed} = \frac{84.7}{5.5} = 15.4 \text{ km/hr} \]
### Step 2: Understand the downstream speed
The downstream speed is the speed of the boat in still water plus the speed of the stream. We can write this as:
\[ \text{Downstream speed} = \text{Speed of boat in still water} + \text{Speed of stream} \]
Using the given values:
\[ 15.4 \text{ km/hr} = 13 \text{ km/hr} + \text{Speed of stream} \]
### Step 3: Find the speed of the stream
To find the speed of the stream, we simply subtract the speed of the boat in still water from the downstream speed:
\[ \text{Speed of stream} = 15.4 \text{ km/hr} - 13 \text{ km/hr} = 2.4 \text{ km/hr} \]
So, the speed of the stream is **2.4 km/hr**.
