Question

A bag contains 14 red marbles and 6 blue marbles. two marbles are randomly drawn without replacement. find the probability that both marbles are red

Answer 1

We take 2 marbles from 20 marbles and the total ways is 20x19:2=190
But we need only 2 red marbles and the ways is 14x13:2=91
And finally we do the division 91:190=91/190 is the probability we need