In a 300 m race, A beats B by 22.5 m or 6 seconds. What is B's time over the course?

Problem restatement
When A finishes 300 m, B is 22.5 m behind; equivalently, B takes 6 s longer to finish the race. Find B's total time for 300 m.

Concept/Approach
The 22.5 m deficit equals B's distance covered in 6 s, which gives B's speed. Then compute time for 300 m.

Step-by-step calculation
B's speed = 22.5 / 6 = 3.75 m/sB's time for 300 m = 300 / 3.75 = 80 s

Verification/Alternative
If B's time is 80 s, then A's time is 74 s (6 s ahead). In 74 s, B covers 3.75 × 74 = 277.5 m, which is 22.5 m short of 300 m (checks).

Common pitfalls
Assuming constant difference in distance translates directly to average speed without using the 6 s information.

Final Answer
80 seconds (i.e., 1 min 20 s)