Which number replaces the question mark?
2024
Which number replaces the question mark?
- A.
8
- B.
7
- C.
6
- D.
5
Attempted by 1 students.
Show answer & explanation
Correct answer: D
Concept: In each star, the number at the centre equals the absolute difference between the sum of the even numbers at the five points of the star and the sum of the odd numbers at the five points.
Star 1: the points are 1, 4, 6, 3, 2. Even points = 4, 6, 2, sum = 12. Odd points = 1, 3, sum = 4. |12 − 4| = 8, which matches the given centre value 8.
Star 2: the points are 4, 11, 9, 2, 8. Even points = 4, 2, 8, sum = 14. Odd points = 11, 9, sum = 20. |14 − 20| = 6, which matches the given centre value 6.
Star 3: the points are 10, 2, 7, 5, 5. Even points = 10, 2, sum = 12. Odd points = 7, 5, 5, sum = 17. |12 − 17| = 5.
Cross-check: The rule is confirmed on both fully-worked stars (centre 8 and centre 6) before it is applied to the third star, so the same computation can be trusted for the missing value.
Answer: 5