In a 1 km race, A beats B by 250 m or by 25 seconds. Find the time taken by A to run 1 km.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 75 sec
"Beats by 250 m or 25 seconds" means that when A finishes, B still has 250 m to run, and B needs 25 seconds for those 250 m. That gives B's speed.
B's speed \(\displaystyle =\frac{250}{25}=10\) m/s
B's time for 1000 m \(\displaystyle =\frac{1000}{10}=100\) seconds
A finishes 25 seconds before B, so A's time \(=100-25=75\) seconds