Solutions

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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 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?


 

Option A:

1/4

Option B:

1/3

Option C:

1/2

Option D:

7/12

Option E:

2/3

Difficulty Level

Hard

Solution

Option C is the correct answer.


Option Analysis

The probability of NOT selecting medium out of 3 sizes = 2/3

The probability of NOT selecting red out of 4 colors = 3/4

Total probability of NOT selecting red and medium = (2/3)*(3/4) = 1/2

Required probability = 1 – 1/2 (this will select at least one of red and medium)

= 1/2