A plane flies at 800 km/h. How many hours does it take to fly 2400 km?

Step by step

The question

Question: A plane flies at 800 km/h.

How many hours does it take to fly 2400 km?

1 Find what we know

What do we know?

The plane goes 800 km in each hour.

The trip is 2400 km.

What do we want?

How many hours.

2 Name the unknown

We don't know how many hours.

So we call it x.

How far we go: speed times time.

800 km/h means 800 km in each hour.

3 Write the equation

In words: speed times time makes the distance.

So the equation is 800x = 2400.

Now we solve it.

4 Remove the 800

800x means 800 times x.

We want just x.

To remove times 800, we divide by 800.

We do it on both sides, so they stay equal.

800 divided by 800 is 1.

So just x is left.

2400 divided by 800 is 3.

So x = 3!

5 Answer the question

So it takes 3 hours.

6 Check

Let's check in the story.

3 hours at 800 km/h: 3 times 800 is 2400 km, like the story says.

So the answer is right!

Let's look back.

First: find what we know.

Then: name the unknown.

Then: write the equation.

Then: solve it.

Then: answer the question.

Last: check.