Finding the distance between slits in double slit experiment

[Bolter]

Homework Statement

See below

Relevant Equations

d=mD*lamba/x

Hi so I have been struggling on a part of a question that I'm not too sure on how to solve
For some reason PF is not allowing me to pose an image of the question on here so I have provided a link to it

Question link:

And here is what I tried to do so far, I drew a sketch of a diagram to help me derive the formula that I need

Sketch:
Working out:

I got little d to be 2.92 x 10-4m

Any help would be really appreciated! Thanks

 

[Charles Link]

I computed it also, and got the same answer.

 

[BvU]

Any help would be really appreciated

Sure. What is your problem ?

 

[Bolter]

Sure. What is your problem ?

Sorry I just got threw off here as it was set to be 12 marks, so I though I had to make use of a diagram or something to get to an equation I can use to find d. And not just dive straight into a known general formula to calculate d, as it would seem to be too much little work.

Looks about right now then I guess

 

[Bolter]

I computed it also, and got the same answer.

Ok thanks for confirming!