In an 800 m race, B's course is only 725 m because A gives B a start. What start (in meters) does B get from A?

Introduction / Context:
When a start is granted, the slower runner covers a shorter distance than the official race length. The size of the start equals the difference between the official length and the reduced course.

Given Data / Assumptions:

• Official race length L = 800 m.
• B's course length = 725 m.

Concept / Approach:
Start s = L - B's course length.

Step-by-Step Solution:
s = 800 - 725 = 75 m

Verification / Alternative check:
Interpretation check: with a 75 m head start, B needs 725 m while A runs the full 800 m. This is the standard meaning of a start in distance terms.

Why Other Options Are Wrong:
22, 35, 45 m are not equal to the required difference of 75 m; they would imply a different reduced course length for B.

Common Pitfalls:
Dividing or scaling by speeds despite not being asked; confusing with time handicaps; arithmetic mistakes in subtraction.

Final Answer:
75 m