A motor boat takes 12 hours to go downstream and it takes 24 hours to return the same distance. What is the time taken by boat in still water ?   Select an answerA15 hB16 hC8 hD20 h

To solve this problem, we need to understand that the speed of the boat in still water is the average of its downstream and upstream speeds.

1. First, we calculate the downstream speed. The boat takes 12 hours to travel a certain distance downstream. Let's denote this distance as D. So, the downstream speed is D/12.

2. Next, we calculate the upstream speed. The boat takes 24 hours to travel the same distance upstream. So, the upstream speed is D/24.

3. Now, we find the speed of the boat in still water, which is the average of the downstream and upstream speeds. So, we add the two speeds and divide by 2: (D/12 + D/24) / 2.

4. Simplifying this expression, we get D/18. This is the speed of the boat in still water.

5. To find the time taken by the boat to travel the distance D in still water, we divide the distance by the speed: D / (D/18) = 18 hours.

So, the time taken by the boat in still water is 18 hours. However, this option is not available in the choices given. There might be a mistake in the problem or the options provided.