There is a point P on the circle. A and B started running in two constant different speeds. A in Clockwise and B in Anti-clockwise. First time 500 m in Clockwise from P then 400 Anti-clockwise. If B is yet to complete one round, What is the circumference of the circle?

• Let the speeds of A & B be u and v resp. and let circumference be C.
  
  Let their first meeting be after time t then ut+vt = C and ut = 500
  
  ∴ vt = C−500 and u/v = 500/(C−500)
  
  For their second meeting after time T, uT+vT = 2C and vT = 400
  
  ∴ uT = 2C−400 and u/v = (2C−400 )/400
  
  Hence 500/(C−500) = (2C−400) /400
  
  Simplifying, 100000 = (C−200)(C−500) = C²−700C+100000 → C=700
• 11 years agoHelpfull: Yes(15) No(1)
• 900m.500m from P clockwise to a point and 400 m from P to same point so total 900m
• 12 years agoHelpfull: Yes(5) No(14)