Question

A certain store sells small, medium and large toy trucks in each of the colors red blue green and yellow. the store has an equal number of trucks of each possible color-size combination. if paul wants a medium red truck and his mother will randomly select one of the trucks in the store, what is the probability that the truck she selects will have at least one of the two features paul wants?
a.1/4
b.1/3
c.1/2
d.7/12
e.2/3

Answer 1

c.1/2
Assume ther is one of each for size/color combo. there are 12 different trucks to choose from. 4 will be medium, 3 will be red. there is one that is red and medium. Add the probability of medium plus the probability of red, minus the probability of both.
$\frac{4}{12} + \frac{3}{12} - \frac{1}{12} = \frac{6}{12}$
6/12 = 1/2.

Answer 2

There is a 1/2 chance that he will get at least one of the two features.

There are 3 x 4 = 12 possibilities. There are all 4 colors of each 3 sizes.

All 4 of the medium trucks have one of the features.

For the other 2 sizes, only the red truck will have one of the features.

There are 4 + 2 = 6 possibilities out of 12 for a chance of 6/12 or 1/2.