Question 1065335
a) The sum of probabilities must equal 1.
b) It will either rain or not rain, there are no other possibilities so the sum of the two probabilities must equal 1.
c) Probabilities must be in the range of [0,1].
d) There are 13 hearts and 52 total cards so the probability of drawing a heart is 
{{{P=13/52=1/4}}}
The probability of selecting a black heart is zero. Hearts are a red suit.