A drawer holds 4 red hats and 4 blue hats. What is probability of getting exactly 3 red hats or 3 blue hats when taking out 4 hats randomly out of the drawer and immediately returning every hat to the drawer before taking out the next?
A
1/2
B
1/4
C
1/6
D
1/8
Correct Option - B
Explaination
P(getting a red hat in 1 draw)
= 4/8 = 1/2
P(getting a blue hat in 1 draw)
= 1/2
P(getting 3 red hats)
= (1/2)*(1/2)*(1/2)
= 1/8
P(getting 3 blue hats)
= 1/8
P(getting 3 red hats or 3 blue hats)
= (1/8)+(1/8)
= 1/4