Question

mary mixes white paint and blue paint in the ratio 2:3 she makes a total of 20 liters of paint how uch more blue paint does she need to add to mixture so that the ratio of white paint to blue pain becomes 1:7

Answer 1

Add 44 litres blue

Explanation:

Mary has 20 liters of paint mixed white:blue in the ratio 2:3. So two fifths of that paint is white and three fifths is blue. So that's 8 liters white, 12 liters blue.

We want to add paint to get white:blue = 1:7. Clearly we need to add blue. We have our 8 liters of white, so we need a total of 7(8)=56 liters of blue. We already have 12, so we have to add 56-12=44 liters of blue paint.

Answer 2

20 liters of paint consist of 2+3 = 5 equal parts; so each part is 4 liters; hence, white paint is 8 liters (and blue paint is 12 liters).

To get the final ratio white to blue as 1:7, Mary must have 7*8 = 56 liters of the blue paint - so she need to add 56-12 = 44 liters.

Answer. 44 liters of the blue paint to add.