In a bag are three red marbles and green marbles if two marbles are drawn from the bag at the same time what is the probability that both marbles will be red?

To find the probability of drawing two red marbles from a bag containing three red marbles and two green marbles (a total of five marbles), you can use the combination formula. The number of ways to choose 2 red marbles from 3 is ( \binom{3}{2} = 3 ), and the total ways to choose 2 marbles from 5 is ( \binom{5}{2} = 10 ). Thus, the probability of drawing two red marbles is ( \frac{3}{10} ) or 0.3.