A bag has three red marbles, two blue marbles, and four yellow marbles. What is the theoretical probability of pulling a red? Write it in simplest form.
A. 1/3
B. 1/9
C. 3/10
D. 3/9
The total number of marbles in the bag is 3+2+4=9.
The probability of pulling a red marble is 3 out of the total 9 marbles.
Therefore, the theoretical probability of pulling a red marble is 3/9.
This fraction can be simplified by dividing both the numerator and denominator by their greatest common factor, which is 3.
3/9 simplifies to 1/3.
So the answer is A. 1/3.