DD.46 Four animals on a rectangle

As shown in the figure, a monkey, a dog, a cat, and a mouse are in each vertex of the rectangle of 4 m long and 8 m wide.
Now, they began to turn around on the side of the rectangle counterclockwise at the same time.
Each speed is that a monkey is at 80 cm/s, a dog is at 60 cm/s, a cat is at 50 cm/s, a rat is at 30 cm/s.
Answer the following questions.

(1) Find the time when four animals pass along the same place at the same time for the first time.

(2) Find the time to come to the vertex at the same time for the first time where each animal is there at first.





Answer
(1) 200 seconds
(2) 240 seconds