Total number of marbles = 10
Number of red marbles = 4
Number of blue marbles = 6
Probability = [tex]\frac{number of favorable outcomes}{total number of outcomes}[/tex]
The probability that the first marble is blue = [tex]\frac{6}{10}[/tex]
The probability that the first marble is red = [tex]\frac{4}{9}[/tex] ; 9 because 1 marble has already been taken out.
Joint probability= probability of event A * Probability of event B
= [tex]\frac{6}{10}\times\frac{4}{9}[/tex]=[tex]\frac{24}{90}= \frac{4}{15}[/tex]