## At some allude or another, most hair colour technicians will need to mix together a couple of various developers in order gain the perfect volume the they need.

You are watching: How to make 40 volume developer

For example, you more than likely will not have actually 25 volume sitting around, therefore naturally, you will certainly mix half of 20 volume and fifty percent of 30 volume in stimulate to do 25 volume.

And say you need to make 20 volume, but you only have 40 volume lying around. Girlfriend would normally mix 1 oz of 40 volume and 1 oz of cream conditioner (or some other neutral mixture) to gain a equipment that averages the end to 20 volume.

This is pretty right forward and something you’re most likely used to doing in the shop anyways.

But….

On her Ontario Hairstylist license exam, you might get a question that look at something favor this:

**Which the the adhering to combinations would develop 30 volume developer?**

**20 + 10 + 20**

**50 + 20 + 20**

**10 + 40 + 20**

**40 + 40 + 20**

Pretty confuse if did you do it never also seen 50 volume and if you’ve never had actually to mix developer this way.

So, here’s a formula I’ve developed that you have the right to use to handle a question favor this on your hair license exam:

**(X1 + X2 + X3 + …) / Y = Z**

Where **X1 , X2 , X3….. **represent** 1 oz of any type of volume of developer**

**Y** to represent the **total variety of ounces the developer**

**Z** to represent the **final volume the the resulting developer**

So based on this formula, the correct answer to the question over is B.

Why?

In the question above, assume the each number you watch represents 1 oz (ounce) that developer, so that there space 3 equal components of 3 different developers.

Since you require 30 volume, and there space 3 ounces of developer in each of the feasible answers, it method that the complete volume of all of those 3 ounces combined when included together must equal come 30 once it is divided into 3 equal parts.

What divided by 3 will equal come 30?....let’s execute some turning back math à 3 x 30 = 90.

Therefore, the exactly answer in the question over must add up to 90 since 90 ÷ 3 = 30.

Only alternative B in the answer over adds as much as 90. 50 volume + 20 volume + 20 volume = 90 volume.

90 volume ÷ right into 3 equal parts = 30 volume.

*We are merely averaging the end the level the the volume when 3 equal sections of different volumes space combined.See more: What Happens If You Sneeze Underwater ? It'S Totally Possible To Sneeze Underwater*

**Another Example:**

You ran the end of 20 volume and also you only have 40 and also 10 volume available. How could you create 20 volume?

You must mix:

1 component 40 + 1 component 10 + 1 part 10

Why:

(40 + 10 + 10) ÷ 3 = 20

Makes sense, right?

Well, i hope I have simplified what may have actually initially seemed favor a tricky or confusing exam question.