Duplicate head-start scenario (sanity check): In a 500 m race, speeds of A and B are in the ratio 3 : 4. A has a start of 140 m. By how many metres does A win?

Introduction / Context:This repeats the earlier head-start calculation to confirm consistency across similar items.

Given Data / Assumptions:Race 500 m; A has 140 m start → A runs 360 m. Speeds A:B = 3:4.

Concept / Approach:B covers (4/3) times A’s distance in the same time. Compute B’s position when A finishes 360 m.

Step-by-Step Solution:

Verification / Alternative check:Consistent with proportional reasoning across similar tasks.

Why Other Options Are Wrong:Mismatch the exact ratio implication.

Common Pitfalls:Ignoring the head-start in required distance for A.

Final Answer:20 m