As we know that,
There are total 52 cards in the deck.
And a deck has 4 types containing 13 cards each.
The types are: spade, club, diamond and hearts.
So, we have an event (A) with total cards = 13
Each card has four types so event (B), that is the number of cards = 4
Now, probability of picking a diamond is p(A) = 13/52 = 1/4
Probability of picking a 6 = 4/52 = 1/13
Now, if you realize that one 6, that is a diamond 6 is common in both the events, that means that p(A and B) /= 0. Hence, these are not mutually exclusive.
Now, The probability in case of nonexclusive events can be calculated as:
P = P(A) + P (B) - P (A and B)
Here, P (A and B) is equal to 1/52 as one card out of 52 is common in both.
Therefore,
P = 1/13 + 1/4 - 1/52
or
P = 4/52 + 13/52 - 1/52
P = 16/52
p = 4/13
Hence, the probability of drawing a 6 or a Diamond is 4/13.