Question

Purple paint is a mix of blue paint and red paint in the ratio of 7:4

Answer 1

So to start you need to add 7 and 4 to get 11
Then you divide 1650mL by 11 which gets you 150mL
You then times that by 7 to get the ratio of blue paint which is 1050mL and times 150mL by 4 to get the ratio of red paint which is 600mL