I multiplied both probabilities so 4/6*3/4 but i got a wrong answer. The answer is c
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.
1/12
B.
4/9
C.
2/3
D.
3/4
E.
4/3
Hey !
You did the right thing, but failed to think about the case where he takes a heart out of the first box (A).
In that case, there would still be a chance that he gets a star out of the second box as it already has 2 stars in there.
You have to do the same calculation for the second option and add the results for the two possibilities 
Heyy, it makes sense now, thanks for that explanation!