IMAT 2011 Q76 [Probability]

David has two boxes containing shapes.

In box A there are 4 stars and 2 hearts.

In box B there are 2 stars and 1 heart.

David takes, at random, a shape from box A and puts it into box B.

He then takes a shape from box B.

What is the probability that this shape is a star?

A. {\frac{1}{12}}

B. {\frac{4}{9}}

C. {\frac{2}{3}}

D. {\frac{3}{4}}

E. {\frac{4}{3}}