Question 1 of 71

The pie chart below shown the number of marbles in a box. $\frac{1}{2}$ of the marbles are green and red. The number of black marbles is $\frac{2}{7}$ the number of white marbles.
Express the number of red marbles as a fraction of the total number of marbles in the box. Leave your answer in the simplest form.

A
$\frac{1}{8}$
B
$\frac{1}{10}$
C
$\frac{1}{12}$
D
$\frac{1}{14}$
E
None of the above