If a random card is drawn from a standard 52 deck?

The two groups 13 spades and 4 sixes counts the six of spade twice

Correct that by calculating 13 + 4 - 1 = 16 cards match the description

Since there are 52 cards in a pack the probability is 16/52 = 4/13

The proper way to set this up:

P( spade or 6 ) = P(spade) + P(6) - P(6 of spades)  = 

       13/52   + 4/52  - 1/52  = 4/13     

there are  13 spades in 52 card deck,  4 cards with a  6 , and 1 card is both a 6 and a spade... the 6 of spades   

P( A or B ) = P(A) +  P(B) -  P(A and  B )   

in  probability math  symbols for       and  is   ∩       or   is     ∪ 

don't forget to choose a Best Answer ...

13 spades

4 6's

1 of which is a spade and a 6

13 + 4 - 1 = 16

16 out of 52 cards fit the bill

16/52 =>

4/13