Answer:
The probability that the truck she selects will have at least one of the two features that Ella Stella wants is 50%.
Explanation:
Since a certain store sells small, medium, and large toy trucks in each of the colors red, blue, green, and yellow, and the store has an equal number of trucks of each possible color / size combination, if Stella wants a medium red truck and her mother will randomly select one of the trucks in the store, to determine what is the probability that the truck she selects will have at least one of the two features that Stella wants, the following calculation must be performed:
3 sizes
4 colors
4 x 3 = 12
4 midsize cars
3 red cars
1 medium red car
4 + 3 - 1 = 6
6/12 = 0.5
Therefore, the probability that the truck she selects will have at least one of the two features that Ella Stella wants is 50%.