The probability is given by the following formula:
Probability = number of favorable outcomes / total number of outcomes
The total number of outcomes is 10, 3 of the initial number of marbles are red and 2 of them are orange.
The probability of getting a red marble in the first draw is:
Probability = 3/10
The probability of getting an orange marble in the second draw is:
Probability = 2/10 = 1/5
the probability that he will choose a red and then an orange marble can be calculated by multiplying the probabilities that we found, then we get:
Probability = 3/10 × 1/5 = 3/150 = 1/50
Then, the answer is 1/50
