the answer is 1200 millimeters per hour
If I've read this correctly, it looks like this.

If that is correct, then the first step is to put the top part of the denominator over 3x
The next part is to flip a three tier fraction. I'm afraid I have to show what happens. My latex is not that strong.
What you get is

This is just about your final answer. You could write it as

The answer is C to this question
Answer:
1/49
Step-by-step explanation:
You wrote the problem correctly. You just needed to multiply instead of add.
1/7*1/7=1/49
So the answer is 1/49.