Final answer:
Tourists can travel 30 km away from the starting point, making the round trip distance also 30 km, as the boat's speed in calm water is 30 km/h and they have 2 hours for the entire trip.
Step-by-step explanation:
The question pertains to finding out how far tourists can travel by boat in a total of 2 hours, considering that the boat's speed in calm water is 30 km/h and they need to return to their starting point. To calculate the total distance they can travel, we need to divide the available time for the one-way trip by 2, because the tourists need time to return. Thus, they have 1 hour for the outbound trip and 1 hour for the return trip.
Using the boat's speed of 30 km/h, we calculate the distance for the one-way trip:
Distance = Speed × Time = 30 km/h × 1 hour = 30 km
The tourists can travel 30 km away from the starting point before they have to head back, making the total distance covered on the round trip also 30 km, as they would travel the same distance back to the starting point.