motion in a closed circuit

Problem
Benjie and Jerwin is running in opposite directions in a 400-meter circular track and meet each other every 35 seconds. If Benjie can complete one track in 65 seconds. How long does it take for Jerwin to run 400 meters?
 

Problem
Runners A and B start together in a race around a 900-ft oval track. Runner A is making a speed of 27 ft/sec and runner B at 22.5 ft/sec. How long will it take runner A to be exactly one circumference ahead of runner B.