Problem
Three boys and four girls enter a contest at the local movie theater. A randomly chosen winner will be awarded a free movie ticket, a collectible poster, or free popcorn. What is the probability that a girl will win free popcorn? (A) \( \frac{3}{21} \) (B) \( \frac{4}{21} \) (C) \( \frac{3}{7} \) (D) \( \frac{4}{7} \)
Solution
Step 1 ：Find the total number of possible outcomes: \( 7 \times 3 = 21 \)
Step 2 ：Find the number of outcomes where a girl wins free popcorn: \( 4 \times 1 = 4 \)
Step 3 ：Calculate the probability: \( \frac{4}{21} \)
