Ellen has a bag with 333 red marbles and 222 blue marbles in it. she is going to randomly draw a marble from the bag 300300300 times, putting the marble back in the bag after each draw.

Do you mean 3 red marbles and 2 blue marbles, and she's going to draw a marble 300 times?
The probability of drawing a red marble is 3/5 = 0.6.
The probability of drawing a blue marble is 2/5 = 0.4.
In 300 drawings, she should expect to draw a red marble 0.6 * 300 = 180 times.
She should expect to draw a blue marble 0.4 * 300 = 120 times.

It's like discovering the answer to a puzzle. the purpose in solving an equation is to find the value or values of the variable that makes it a true statement. any value of the variable that makes the equation true is called a solution to the equation.