fozzzy wrote:

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 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

let there be x number of trucks of all possible color-size combination.

probability that the truck she selects will have at least one of the two features Paul wants can be found by subtracting the probability of selecting a truck that doesn't has either of the property i.e. it is neither red in color nor of medim size from 1.

In the diagram attached, the I crossed off all the desired results i.e. cancelled all the possible combination of red-medium.

# of remaining outcomes= # of blue circles = # of trucks that don't have either of the desired property.

No. of colors=4

no. of sizes=3

Total outcomes=12

Remaining outcomes=6

hence probability that truck is neither red nor of medium size is \(6/12\).

hence probability that the truck she selects will have at least one of the two features Paul wants will be \(1 - 6/12\) or \(1/2\)

+1C

never thought of table usage for probability . Good strategy.