At a certain paint store forest green is made by mixing 4 parts blue paint with 3 parts yellow paint.Verdant green is made by mixing 4 parts yellow paint with 3 parts blue paint.How many liters of yellow paint must be added to 7 liters of forest green to change it to Verdant green?	Select the correct option
A) 5 / 3 B) 2 / 7 C) 7 / 3 D) 1 / 7 E) 1 / 4

Rationale: 7 liter of forset green have 4 liter of blue and 3 liter of yellow suppose we add x liter of yellow to make it a verdant green so the ratio of blue to yellow in verdant green is ¾ so the equation is blue / yellow = 4 / ( 3 + x ) = ¾ 9 + 3 x = 16 = > x = 7 / 3 answer : c
Answer: C