Question

A bag contains 10 marbles: 3 are green, 2 are red, and 5 are blue. Jose chooses a marble at random, and without putting it back, chooses another one at random. What is the probability that the first marble is red and the second is blue? Write your answer as a fraction in simplest form.

Answer 1

we know that
g=3
r=2
b=5
total marbies=g+r+b------> 3+2+5----> 10

a) probability that the first marble is red
P(red)=r/total marbies------------> 2/10-----> 1/5

b) probability that the second marble is blue
in this case total marbles-------> 9
P(blue)=b/total marbles----------> 5/9

c) the probability that the first marble is red and the second is blue
(1/5)*(5/9)=1/9

the answer is
1/9