Back to Questions
EEJ MAIN Mathematics
QUESTION #6935
Question 1
A class has 5 girls and 7 boys. Teams of 2 girls and 3 boys are to be formed. However, two specific boys A and B cannot both be on the same team. How many valid teams can be formed?
Correct Answer Explanation
Total teams (no restriction): $\binom{5}{2}\binom{7}{3} = 10 \times 35 = 350$
Teams where both A and B are included: Choose remaining 1 boy from 5 others: $\binom{5}{2}\binom{5}{1} = 10 \times 5 = 50$
Valid teams $= 350 - 50 = \mathbf{300}$
Sign in to join the conversation and share your thoughts.
Log In to Comment