CEMC Cayley, 2007

Algebra Difficulty 2.0 Junior Find the answer Canada

There are a certain number of red balls, green balls and blue balls in a bag. Of the balls in the bag, $\dfrac{1}{3}$ are red and $\dfrac{2}{7}$ are blue. The number of green balls in the bag is $8$ less than twice the number of blue balls. The number of green balls in the bag is

(A) $12$ (B) $16$ (C) $20$ (D) $24$ (E) $28$

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