Budget Quantity formula

This is perhaps more a general math question but the solution will be used in excel...

I have a monthly budget i.e £20,000
Each month this is split using a percentage ratio, 5%, 35% & 60% based on 3 values of products.
Option 1 - 5% - £1000
Option 2- 35% - £600
Option 3 - 60% - £100

What I need to find out from the information above is the quantity of each option I can get closest to the percentage ratio set each month.

Not knowing the total quantity of products to easily calculate this, is the problem. How do I work this out?! So we can work out how many of each option we can get at the % ration, without using trial and error.

Can you provide an example of the solution?!

That doesn't give me the quantity as a %.

The answers you have provided are, 1, 11 & 120 which means the quality of option 1 isn't 5% of 131.

Do you see what my problem is?! Not so straight forward :-(

I realise this is confusing and I'm not the best at explaining my problem.

Here is what I know:
- the budget value
- the product values (3 different values)
- the % split I need the total number of products split by.

The % split is on quantity, this is the figure I don't have.

Take a basic example:
Budget £15,400

Product 1 - £100
Product 2 - £10
Product 3 - £1

If we want the % split in in quantity to be:
Product 1 - 10% of total quantity
Product 2 - 50% of total quantity
Product 3 - 40% of total quantity

If we knew the total quantity was 1000, our split would be:
Product 1 - 100 (£10,000) %10
Product 2 - 500 (£5,000) %50
Product 3 - 400 (£400) %40

Does that make it any clearer?! I'm struggling to explain it any further sorry.

Wow! The solution seems to be exactly what I am after. :-)

I'm just going to test this on a few other variable and get back to you ... Thank you all for your help!!!

The solution is perfect!