The speed of a boat in still water is 15 km/hr. It can go 30 km upstream and return downstream to the original point in 4 hours 30 minutes. Find the speed of the stream.

Explanation

To solve the problem, we need to find the speed of the stream (let's denote it as \( x \) km/hr). The speed of the boat in still water is given as 15 km/hr. The boat travels 30 km upstream and then returns downstream to the original point in a total time of 4 hours and 30 minutes.

### Step-by-Step Solution:

1. **Convert the total time into hours:**
\[ 4 \text{ hours } 30 \text{ minutes} = 4 + \frac{30}{60} = 4.5 \text{ hours} \]
...