Answer:
(1) 
(2) 
(3) 
(4) 
Step-by-step explanation:
(1). A bag has 5 red marbles, 6 blue marbles and 4 black marbles.
Total marbles in a bag = 5 + 6 + 4 = 15 marbles
The probability of picking a red marble
=
= 
By replacing it and then picking another red marble
=
= 
P =
×
= 
(2). A bag has 5 red marbles, 6 blue marbles and 4 black marbles.
Total marbles in a bag = 5 + 6 + 4 = 15 marbles.
The probability of picking a blue marble =
=
= 
replacing it and then picking a black marble =
= 
P =
×
= 
(3). A bag contains 4 white, 3 black and 5 red marbles.
Total marbles = 4 + 3 + 5 = 12 marbles
The probability of picking a red marble = 
(4). A bag contains 3 white marbles, 2 black marbles and 5 red marbles.
Total marbles = 3 + 2 + 5 = 10 marbles.
The probability of picking a white marble = 
(1) 
(2) 
(3) 
(4) 