Final answer:
To determine the time taken by the ship to travel 208 km downstream, we add the ship's speed in still water to the stream's speed to get the effective downstream speed, then divide the distance by this effective speed, resulting in 8 hours.
Step-by-step explanation:
The student has asked: "If the speed of a ship is 20 km/hr in still water and the speed of the stream is 6 km/hr, find the time taken by the ship to travel 208 km downstream."
To solve this, we must first calculate the effective speed of the ship downstream by adding the speed of the ship in still water and the speed of the stream.
Effective speed downstream = Speed in still water + Speed of stream = 20 km/hr + 6 km/hr = 26 km/hr.
Next, we use the formula Time = Distance ÷ Speed to find the time it takes to travel 208 km downstream.
Time taken = Distance ÷ Effective speed = 208 km ÷ 26 km/hr = 8 hours.
Therefore, the correct answer is (a) 8 hr.