CEMC Cayley, 2001

Algebra Difficulty 1.0 Junior Find the answer Canada

In a school, 30 boys and 20 girls entered the Cayley competition. Certificates were awarded to 10% of the boys and 20% of the girls. Of the students who participated, the percentage that received certificates was

(A) $14$ (B) $15$ (C) $16$ (D) $30$ (E) $50$

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