You now know that 45ml is 5 parts so to find one part you need to work out 45 divided by 5 which is 9ml. Once you know what one part if the rest of the equation is straight forward with you just needing to add up all the various parts in the recipe. Good Luck.
Wouldn't be easier to say you have 9 lots of fruit puree so altogether you would have 9 lots of the total of 12parts which is 108. This avoids lots of fraction work and is quicker.