Find the area of a non shaded area​

We can first add up the cards so we know how many we have in all:
16 + 16 + 18 = 50 cards

We can do this a little bit easier if we get the "16"-cards in one number total.

16 + 16 = 32

= 32 x 2 = 
                                         50 x 2 

= 64 : 2 = 32 %
                                            100
We did just divide the % of two types cards on 2, so we get the %-chance of 1 type card.

I am not quite sure, but I think that 32 % is the correct answer.