2015 · Q28
A run 12/3 times as fast as B. If A gives B a start of 80 m, how far must the winning post from the starting point be so that A and B might reach it at the same time?
Elementary MathematicsTime, Speed and Distance
- A200 m
- B300 m
- C270 m
- D160 m
Explanation
A runs 1⅔ = 5/3 times as fast as B (the text '12/3' is an OCR rendering of 1⅔). If A runs 200 m, B runs 200 × 3/5 = 120 m in the same time, exactly using up B's 80 m head start (200 − 120 = 80). So the winning post is 200 m away (option A).