How Do You Calculate the Spacing Between Diffraction Grating Grooves?

[J89]

Homework Statement

You will need to know the spacing d between grooves on the diffraction grating used in the lab. If the this diffraction grating has 13400 grooves per inch, how many grooves per meter does it have?

Homework Equations

1 inch = 39.37 meters

The Attempt at a Solution

You just multiply 39.37 by 13400 and get 527558..however, the only question is what is the units dealing with groove? I insert in my online homework assignment..it's marked as wrong!

 

[Doc Al]

You just multiply 39.37 by 13400 and get 527558..however, the only question is what is the units dealing with groove? I insert in my online homework assignment..it's marked as wrong!

To convert from grooves per inch to grooves per meter, yes you multiply as you did. But is that the question? Or is the question what is the spacing between the grooves?