Boat and Stream Math Problem Solution 🛥️

A boat running downstream covers a distance of 16 km in two hours, while for covering the same distance upstream, it takes four hours.

What is the speed of the boat in still water?

So I will say there's going downstream and then there's going upstream, and the distance is the same.

Now, they tell me that going downstream it does 16km in two hours.

Now, what's the speed?

Well, there's the speed of the boat and then there's the speed of the current.

And so I'm going to say that that is S for boat speed plus C, which is the current.

And then on the return trip, the distance is the same.

How long does it take?

Four hours.

And what is that speed?

It's going to be the speed of the boat against the current.

Now, do I have to create some kind of an equation and plug one into the other?

In this case, no, because I can do the following.

I can simplify both equations to the following.

The first one becomes S plus C equals 8, and the second one becomes S minus C is equal to 4.

And if I notice this plus and minus, and I decided to add the equations, I just get rid of the C, so I don't even need to find the speed of the current.

And so what I have is 2s equals 12.

Therefore, the speed of the boat in still water is 6 kilometers per hour.