Your answer is very close to being correct; however, the true answer is actually

without any parenthesis needed around the fraction. Notice how there is no (x) at the end.
THis is a binomial distribution:-
P( 3 tails) = 15C3 (0.5)^3(0.5)^12
= 0.0139
P(5 tails) = 15C5 (0.5)^5(0.5)^10
= 0.0916
P(3 or 5) = 0.0139 + 0.0916 = 0.1055 Answer
Answer:
4(x + 8)
Step-by-step explanation:
4x and 32 are both divisible by 4, so divide the equation by 4, and multiply the 4 by the result, which is x + 8, so the answer is 4(x + 8) because x + 8 cannot be simplified anymore.
Answer:
a) 
b) 
Step-by-step explanation:
Number of balls in the urn = 12
Number of white balls in the urn = 4
So, number of balls which are not white = 12 - 4 = 8
We know that probability = No. of outcomes/Total number of outcomes
Let
denotes the event of getting white ball by A, B and C
a) each ball is replaced after being drawn.
Probability = Number of white balls/Total number of balls
Solution: 
b)the balls that are withdrawn are not replaced.
Solution:
If A wins: 
If A lost and B wins: 
If A and B lost and C wins: 
and so on....