Question

A bag contains three white two blue and Five red marbles a single marble is pick from the back been put back into the bag and another marble is picked find P (white then red)

Answer 1

The bag contains 3 white marbles, 2 blue marbles, and 5 red marbles.

The probability of picking a white marble followed by a red marble with replacement is;

$Pr(W\&R)=Pr(W)\times Pr(R)$

From the information given, we can deduce;

$\begin{gathered} Pr(W)=\frac{3}{10} \\ Pr(R)=\frac{5}{10} \end{gathered}$

Therefore, we have;

$Pr(W\&R)=\frac{3}{10}\times\frac{5}{10}=\frac{15}{100}=\frac{3}{20}$

Therefore, the probability of picking a white ball followed by a red ball with replacement is 3/20.