Here are some of the ingredients for bolognese sauce: 400g minced beef. 800g chopped tomatoes. 600ml stock. 300ml red whine. julie only has 300g of mince beef. how much of the other ingredients should she use? g chopped tomatoes. ml stock. ml red whine.

600g chopped tomatoes. 
450ml stock.
225 ml red wine.

To find this answer you take what you have and divide it by what you need, in this case it was a 3/4 ratio, or .75. Next you would multiply everything else by that number in order to make everything else has that same 3/4 ratio as the first ingredient. 

Hope this helped :)