Question 1128273
Hi

a) there are 13 hearts in a deck and a deck consists of 52 so 
13/52 = 0.25

b) black cards are equal to half the deck so 
26/52 = 0.5

c) there are 4 fours and 4 eights in the deck so it is a 4 in 52 chance + a 4 in 52 chance = 8 in 52 chance
8/52 simplified to 2/13 if you wish

d) There are 2 red queens so it is a 2 in 52 chance which is a 1 in 26 chance

Hope this helps