Using ratio to work out hair dye and developer proportions

Speaker 1: So Megan, what is it we're doing for you today?

Speaker 2: I'm thinking about going maybe a bit lighter today.

Speaker 1: So, something along these lines?

Speaker 2: Yeah, that looks lovely.

Speaker 1: Yeah? Great. OK, we'll just go and get mixed up for you.

Speaker 2: Thank you.

Speaker 1: Caitlin? Could we get 200ml of 10N mixed please?

Speaker 3: Yep.

Speaker 1: Thank you very much.

Speaker 3: (TO AUDIENCE) Right, so I know when I'm mixing hair colour, I need two ingredients, the colour and the developer.

And I know you have to get the amounts exactly right, because if you don't, you don't get the right colour in the end, or worse, you could damage the client's hair.

So a tube of colour is 60ml, and I need a total mix of 200ml of colour and developer.

I know when you mix hair colour and developer, you have to mix it at a ratio of 1 to 1.

So for every 60ml of colour, I need 60ml of developer.

Speaker: So I have 60ml of developer, and I need to mix it in a ratio of 1 to 1 with 60ml of colour.

If I add the 60 and the 60 together, I'll get 120ml in total.

But I need 200ml. To get the 2 parts, I need to divide 200 by 2, and I'll get 100.

Right, so 100ml of developer, and now for the colour.

Uh, hang on, this colour says to mix in a ratio of 1 to 1.5.

What's that going to mean?

Speaker 1: (TO AUDIENCE) I've just found out that I need to mix some hair colour in a ratio of 1 to 1.5, not the usual 1 to 1.

I'm glad I checked now. I've already measured out 100ml of developer.

I hope this means I haven't wasted any products.

A ratio of 1 to 1.5, that's quite hard, but if I double both sides, I get 2 to 3.

So that means I have 5 parts in total, which should add up to 200ml.

So 200ml divided by 5 equals 40.

And then I multiply it back up.

So 2 parts will be 2 times 40.

And 3 parts will be 3 times 40.

That's 80ml of colour, and 120ml of developer.

Great, that means I haven't wasted any developer because I've weighed out 100 already, and I actually need a bit more, 120ml, and 80ml of colour.

So that's 1 whole tube and 20ml of a second tube.

Speaker 2: (TO OTHER PEOPLE) Hiya, how you getting on?

Speaker 1: Good, so at first I thought it was 1 to 1, but then I checked the tube, and it's actually 1 to 1 and a half.

Speaker 2: Lucky thing you checked, well done.