Mandy is asked to find the probability of rolling a 3 on a die and drawing an ace of spades from a deck of cards. this is a compound event.

-- There are 6 numbered faces on the die.
Only one of them is the 3.
The probability of rolling the 3 is            1/6 .

-- There are 52 cards in a deck.
Only one of them is the ace of spades.
The probability of drawing it is                  1/52 .

-- The probability of both of these things happening is

                 (1/6) x (1/52)  =  ( 1/312 )  =  0.003205... (rounded)

                                                             =  0.32 % .

The probability of event A 'rolling a 3 on a die' is 1/6. The probability of event B 'drawing an ace of spades from a standard deck of 52 cards' is 1/52. These two events are independent. Therefore the probability of both events occurring is the product of the two values of probability.