Multiple choice general knowledge math & puzzles

Each child in a family has at least 5 brothers and 4 sisters. What is the smallest number of children the family might have?

  1. 9

  2. 10

  3. 11

  4. 12
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For each child to have at least 5 brothers, we need at least 6 boys (each boy has 5 brothers). For each child to have at least 4 sisters, we need at least 5 girls (each girl has 4 sisters). The minimum total is 6 + 5 = 11 children.

AI explanation

If a child is male, he needs at least 5 brothers, meaning there must be at least 6 boys in total (5 others plus himself). If a child is female, she needs at least 4 sisters, meaning there must be at least 5 girls in total (4 others plus herself). Combining the minimum requirements (6 boys and 5 girls) gives a minimum family size of 11 children, satisfying both the brother and sister conditions for every child.

Keep practicing — related questions