Hey there :)
The ratio that the painter needs to use is:
Green : Yellow
4 : 7
28 : p (Let p represent how much liters needed of yellow paint is required)
We can cross multiply, which is the ideal method
4 × p = 7 × 28
4p = 196
Divide by 4 on either side to isolate p
[tex] \frac{4p}{4} = \frac{196}{4} [/tex]
p = 49
[tex]\boxed { Therefore, \ Your \ Answer \ will \ be \ option \ D. \ 49}[/tex]