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b)the balls that are withdrawn are not replaced.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....
Answer:
96 in
Step-by-step explanation:
Answer:
B
Step-by-step explanation:
B Rounded to nearest ten thousand
Answer : No solutions
(I tried making it as detailed as possible, I apologize if you don’t understand it)
For every 7 boys there are 5 girls.
Divide the number of boys by the ratio for boys: 28 / 7 = 4
Now multiply that by the ratio for girls:
4 x 5 = 20
There are 20 girls.