"A" and "B" run around a circular track starting from the same point simultaneously in the same direction. "A" meets "B" for the first time when "A" is exactly in the middle of his 5th round. If "A" is faster than "B" and take 70 seconds to complete 1 lap, how long will B take to complete 1 lap?
Choices: A) 90 seconds B) 54.44 seconds C) 110 seconds D) 63 seconds E) 77 seconds
A is faster than B. Every second he increases distance between A and B. They will meet for the first time again when he increases distance between them by one full circle. (Say the lap is of 100m. He keeps increasing distance between them. When he is 90 m ahead of him, it is the same as 10 m behind him because they are moving in a circle. Finally when he is 100 m ahead of him, he is exactly 1 lap ahead and hence both are at the same point).   A takes 70 secs for one full lap. So he covers 4.5 laps in exactly   70*4.5= 
<gadget id="calculator">  70*4.5</gadget>
<output>315</output>
315 seconds.   In 315 secs, B completes 3.5 laps. So for each lap, he takes  315/3.5= 
<gadget id="calculator"> 315/3.5</gadget>
<output>90</output>
90 secs   90 secondsnswer (90 seconds)
<result>A</result>
"A" and "B" run around a circular track starting from the same point simultaneously in the same direction. "A" meets "B" for the first time when "A" is exactly in the middle of his 5th round. If "A" is faster than "B" and take 70 seconds to complete 1 lap, how long will B take to complete 1 lap?