SOLUTION: A box contains 5 white balls, 3 black balls, and 2 red balls. A-What is the probability of drawing a white ball? B- How many white balls must be added to the box so that the prob

Algebra ->  Probability-and-statistics -> SOLUTION: A box contains 5 white balls, 3 black balls, and 2 red balls. A-What is the probability of drawing a white ball? B- How many white balls must be added to the box so that the prob      Log On


   

Question 587136: A box contains 5 white balls, 3 black balls, and 2 red balls.
A-What is the probability of drawing a white ball?
B- How many white balls must be added to the box so that the probability of drawing a white ball is 3/4?
C-How many black balls must be added to the original assortment so that the probability of drawing a white ball is 1/4?
Please help me with this!
Found 2 solutions by edjones, filboi:
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
A)
5+3+2=10
5/10 = 1/2 the probability of drawing a white ball.
.
B)
(5+x)/(10+x) = 3/4
5+x = 3(10+x)/4
5+x=(30+3x)/4
20+4x=30+3x
x=10 white balls must be added to the box so that the probability of drawing a white ball is 3/4
.
C) Similar to B
.
Ed

Answer by filboi(35) About Me  (Show Source):
You can put this solution on YOUR website!
The solution for C is not similar to B.
Here's the solution:
C. (5)/(10+x) = 1/4
10 + x = 20
x=10
10 black balls must be added so that the probability of drawing a white ball is 1/4.