Four runners A, B, C and D are running around in a circle, 2430 meter in circumference, at 30 mpm, 24 mpm, 20 mpm and 12 mpm respectively. If they start at the same time from the same point in the same direction, when will they be together again?
Explanation:
A, meets D in every 243030-12 = 135 minutes
A meets B in every 243030-24 = 405 minutes
A meets C in every 243030-20 = 243 minutes
∴ A will meet B, C and D in every LCM (135, 405 and 243) i.e. 1215 minutes or 20 hours and 15 minutes.
Hence, option (d).
» Your doubt will be displayed only after approval.
Help us build a Free and Comprehensive Preparation portal for various competitive exams by providing us your valuable feedback about Apti4All and how it can be improved.