Difficulty: Easy
Correct Answer: 10 points
Explanation:
Given data
Concept/Approach
Use relative strengths: A : B : C = 100 : 80 : 72 ⇒ B : C = 10 : 9. If B plays to 100, C will score proportionally 90; hence B can spot C (100 − 90) points.
Step-by-step calculation
B : C = 80 : 72 = 10 : 9If B's target = 100, then C's corresponding score = 100 × (9/10) = 90Points B can give C = 100 − 90 = 10 points
Verification/Alternative
Check transitivity: A:B = 100:80 and A:C = 100:72 ⇒ B:C = (80:72) = 10:9, consistent.
Common pitfalls
Subtracting given advantages directly (20 − 28) instead of using ratios; always compare via common baseline.
Final Answer
10 points
Discussion & Comments