Taro walks around a certain pond with fixed speed and Jiro runs with fixed speed to opposite direction.
Taro passed by Jiro again 10 minutes after passing by Jiro.
Just after first passing, Taro also started running increasing the speed by 120 m/m more than the speed at walking.
Then he passed by Jiro 6 minutes afterward again.
Answer the following questions.
(1) Find the surrounding length of the pond.
(2) After passing first, in order to pass again in 4 minutes and 48 seconds, find the speed per minute which Taro increases from the speed at walking first.
(3) If Taro runs with speed twice the speed of walking first after passing first, he will pass again in 7 minutes and 12 seconds.
Find the speed per minute of Jiro.