1. Dogs running back and forth:

Party A and Party B walk opposite each other at a distance of100km. The speeds of A and B are 6 km and 4 km respectively. A took a dog, set out with A at the same time, and ran back to A when he met B; When I met A, I ran back to B .. and so on until A and B met. The speed of the dog is 10 km per hour. How many kilometers did the dog run?

2. Tiger and Fox:

A tiger found a fox at a distance of 10 meters, and immediately jumped on it. The tiger runs 7 steps, and the fox runs 1 1 step, but the frequency of the fox is fast. Tigers can run three steps, and foxes can run four. Can the tiger catch up with the fox? How many meters will the tiger run if it can catch up?

3. Cattle eat grass.

There are three pastures where the grass grows dense and fast. Their areas are 10/3 mu, 10 mu and 24 mu respectively. The first pasture can feed 12 cows for 4 weeks, and the second pasture can feed 2 1 cow for 9 weeks. If the third ranch is to keep 18 weeks, how many cows will this ranch keep?

Zodiac chart:

The Zodiac, also known as the Zodiac, is twelve kinds of animals in China that match the twelve earthly branches according to the year of birth, including rats, cows, tigers, rabbits, dragons, snakes, horses, sheep, monkeys, chickens, dogs and pigs.

The zodiac is an intuitive representation of the twelve earthly branches, namely, Zi (mouse), Ugly (ox), Yin (tiger), Mao (rabbit), Chen (dragon), Si (snake), Wu (horse), Wei (sheep), Shen (monkey), You (chicken) and Xu (chicken).

With the development of history, it has gradually integrated into the concept of folk belief, which is manifested in marriage, life, annual luck and so on. Each zodiac has rich legends, forming a conceptual interpretation system and becoming an image philosophy in folk culture, such as the zodiac in marriage, the blessing in temple fairs, the year of birth and so on.