In a 1 km race, A beats B by 200 m or by 40 seconds. Find the time taken by A to run 1 km.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 160 sec
"Beats by 200 m or 40 seconds" means that when A finishes, B still has 200 m to run, and B needs 40 seconds for those 200 m. That gives B's speed.
B's speed \(\displaystyle =\frac{200}{40}=5\) m/s
B's time for 1000 m \(\displaystyle =\frac{1000}{5}=200\) seconds
A finishes 40 seconds before B, so A's time \(=200-40=160\) seconds