Suppose [a b] denotes the average of a and b, and \{a b c\} denotes the average

**Answer Choices**

A. \dfrac{2}{9}

B. \dfrac{5}{18}

C. \dfrac{1}{3}

D. \dfrac{7}{18}

E. \dfrac{2}{3}

Suppose [a b] denotes the average of a and b, and \{a b c\} denotes the average

**Answer Choices**

A. \dfrac{2}{9}

B. \dfrac{5}{18}

C. \dfrac{1}{3}

D. \dfrac{7}{18}

E. \dfrac{2}{3}