Answer:
is this the full question: Two boys A and B are at two diametrically opposite points on a circle. At one instant the two start running on the circle; A anticlockwise with constant speed v and B clockwise with constant speed 2v. In 2 minutes, they pass each other for the first time. How much later will they pass each other for the second time?
if yes than this is the answer:-
A speed = v
B speed = 2v
Time to meet = 2 minutes
d= pi r ( distance they have to run to meet)
they are running towards each other.
(2v+v)
speed = 3v
d=rt
pi*r = 3v*2
r= 6v/pi
circumference = 2* pi*r
=2*pi*(6v/pi)
=12v
...
Now distance to travel to meet = 12v
speed = 3v
t=d/r
t= 12v/3v
t= 4 minutes
I hope this helps a little bit.