Question

A bag contains $6$ red balls and $4$ green balls. One red ball is removed from the bag. Find the new probability of selecting at random a green ball?

Answer 1

Step 1 Finding the total number of outcomes and the number of favorable outcomes:

The event is selecting a ball at random.

The total number of balls is,

$$\begin{gathered} Totalnumberofballs=RedBalls+GreenBalls \\ Totalnumberofballs=6+4 \\ Totalnumberofballs=10 \end{gathered}$$

Henceforth, there are $10$ balls placed in a bag. Out of that, $1$ red ball is removed from the bag.

So, the total number of outcomes is $9$.

Out of the total balls, $5$ are red and $4$ are green.

There are $4$ green balls in the bag.

So, the number of favorable outcomes is $4$.

Step 2 Finding the probability of selecting a green ball:

The formula for probability is,

$$\begin{gathered} \Rightarrow Probability=\frac{Numberoffavorableoutcomes}{Totalnumberofoutcomes} \\ \therefore P\left(green\right)=\frac{4}{9} \end{gathered}$$

Therefore, the probability of selecting a green ball is $\frac{4}{9}$.