A and B start together from the same point on a 400 m circular track and run in the same direction at 5 m/s and 3 m/s. After how many seconds do they first meet again?

50 secondsCorrect answerYour answer80 secondsCorrect answerYour answer

\frac{400}{3}

secondsCorrect answerYour answer200 secondsCorrect answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer D

Correct answer: D

Worth noting

50 seconds adds the speeds, which is right only when they run towards each other.

Ten questions from Races & Games, at your own pace.

Explanation