I need to edit my model to include the cost of flights. Now there are a couple of changes we need to make here, and we need to make them to the cost section and the other section for number of flights and the output section.

This is an enormous opportunity to use matrix integrity, keep everything in the same order wherever you are. So I'm going to insert two lines here. So right click insert underneath the assumptions, I'll do the same. Click on two lines, right click inserts, and then do the same thing just at the bottom of the outputs, just above the costs inserts. And I want to make sure that I have my assumptions in the same order. So I am going to have my shorthaul above my long haul. So I'll start off with the shorthaul cost per participant.

And I'll cheat a little bit here I can just drag that down. I can change the word short to long. For my assumptions other, again, I'll put it in the same order. I need the number of shorthaul flights.

Drag it down, change short to long.

And now shorthaul flights cost.

Drag it down, update it to long.

Now I've got everything in the same order. It's going to make it much easier for me to build up my formula at the bottom here.

So short haul cost per participant, we're told it's 300 for the short, 600 for the long.

The number of short haul flights for course one that was 150. And then the number of long haul was 50.

Course Two, it's 24 and one. Now I do notice here that my formatting hasn't quite worked out in this section. That's great. It's an opportunity for us to copy paste formatting. So let's grab a cell that's working. Let's go to the home ribbon. I'm going to use Format Painter, so I just double click on it and then apply it just click to the cells where I need to paste the formatting. Great, that looks much better. Now we go to the bottom and I can build up my formula. So I press equals, and I'm going to start with the short haul cost per participant. I'll multiply it by the number of shorthaul flights. Great. But I want to be able to copy this to the right. I can see that this 300 here, that's in C33, when I copy this formula to the right, that's going to move to D33. Rubbish. I don't want that. I need it to stay in C. So I'll put a dollar sign before the C press enter. That's great. Let's now drag that to the right.

Drag it down. Let's check what it's linking to. That has worked out beautifully. Great.