Answer:
[tex]Probability = \frac{1}{5}[/tex] or [tex]Probability = 0.2[/tex]
Step-by-step explanation:
Given
[tex]Black = 25[/tex]
[tex]White = 35[/tex]
[tex]Red = 40[/tex]
Required
Determine the probability of selecting Black and Red
First, we need to calculate the number of red and black balls
The probability is calculated as thus:
[tex]Probability = P(Black\ and \ Red) \ or\ P(Red\ and \ Black)[/tex]
Convert to mathematical expressions
[tex]Probability = [P(Black) *P(Red)] + [P(Red) *P(Black)][/tex]
Solve for each probaility;
[tex]P(Black) = \frac{Black}{Total} = \frac{25}{100}[/tex]
[tex]P(Red) = \frac{Red}{Total} = \frac{40}{100}[/tex]
So, we have:
[tex]Probability = [P(Black) *P(Red)] + [P(Red) *P(Black)][/tex][tex]Probability = [\frac{25}{100} *\frac{40}{100}] + [\frac{40}{100} *\frac{25}{100}][/tex]
[tex]Probability = [\frac{1000}{10000}] + [\frac{1000}{10000}][/tex]
[tex]Probability = [\frac{1}{10}] + [\frac{1}{10}][/tex]
[tex]Probability = \frac{1+1}{10}[/tex]
[tex]Probability = \frac{2}{10}[/tex]
[tex]Probability = \frac{1}{5}[/tex]
or
[tex]Probability = 0.2[/tex]