Answer:
The required probability is 0.1.
Step-by-step explanation:
red balls = 3
yellow balls = 2
blue balls = 5
Selected balls = 5
Number of elemnets in sample space = 10 C 5 = 1260
Ways to choose 1 red ball and 4 other colours = (3 C 1 ) x (7 C 4) = 105
Ways to choose 5 balls of other colours = 7 C 5 = 21
So, the probability is
I'm guessing the sum is supposed to be

Split the summand into partial fractions:


If
, then

If
, then

This means

Consider the
th partial sum of the series:

The sum telescopes so that

and as
, the second term vanishes and leaves us with

It would be 9!!!
Hope that helps!!!
The answer to this question is C I just worked it out on paper using a calculator