Question 1204014
.
A bag contains three black balls,four white balls and five red balls.
Three balls are removed without replacement.
What is the probability of obtaining; 
(a) One of each colour.
(b) At least two red balls
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


<pre>
(a)  P = {{{(C[3]^1*C[4]^1*C[5]^1)/C[3+4+5]^3}}} = {{{(3*4*5)/C[12]^3}}} = {{{60/220}}} = {{{3/11}}}.    <U>ANSWER</U>


(b)  P = {{{(C[5]^2*C[3+4]^1 + C[5]^3)/C[12]^3}}} = {{{(10*7+10)/220}}} = {{{80/220}}} = {{{4/11}}}.    <U>ANSWER</U>
</pre>

Solved.


----------------


To see many other similar &nbsp;(and different) &nbsp;problems solved, &nbsp;look into the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/Probability-and-statistics/Elementary-Probability-problems-related-to-Combinations.lesson>Elementary Probability problems related to combinations</A> 

in this site.


Learn the subject from there.