Geometry

Question Analysis
This question focuses on calculating the probability of three consecutive dependent events.
The core lies in precisely determining the probabilities of each draw as the composition of toys in the box changes with each removal, and correctly applying the multiplication rule for multiple dependent events.

Key Concept Explanation
Dependent events signify that the result of each preceding draw impacts the probabilities of subsequent draws.
As a toy is taken out, both the total number of toys and the quantity of each type of toy in the box vary, thereby influencing the likelihood of drawing a specific type of toy in the next draw.

Step-by-Step Solution
Calculate the probability of drawing a car on the first draw:
There are 3 cars out of 10 total toys, so .
Calculate the probability of drawing a doll on the second draw given that a car was drawn on the first draw:
After removing one car, there are 9 toys left, and 4 of them are dolls. So .
Calculate the probability of drawing a building block on the third draw given that a car was drawn first and a doll was drawn second:
After removing a car and a doll, there are 8 toys left, and 3 of them are building blocks. So

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