Question

In a bag there are 4 blue marbles,8 red marbles, and 5 orange marbles. if two marbles are drawn without replacement find the probability that both marbles are the same color, the second marble being red. the first being blue the second being orange

Answer 1

P( both same colour) = P(both blue) + P(both red) + P(both orange)

=  4/17 * 3/16 + 8/17 * 7/16 +  5/17 * 4/16  =  3/68 +  7/34 + 5/68  =  11/34 Answer

P( second marble being red)  = P(first marble not being red) * P( second being red)

= 9/17 * 8/16 = 9/17 * 1/2 = 9/34 answer

P(first ble and second orange) = 4/17 * 5/16 =   5/68  answer