Answers to 100 lessons It takes four days for one master to cooperate with three apprentices, and three days for two masters to cooperate with one apprentice. How many days does it take for the apprentice to complete the work alone?

It takes four days for a master to cooperate with three apprentices, so it takes one day for four masters to cooperate with 12 apprentices to complete the work;
It takes three days for two masters and one apprentice to complete this condition,
In order to complete the work in one day, it needs the cooperation of 6 teachers and 3 apprentices
(6-4) Master = (12-3) apprentice;
Namely: the efficacy of master = 4.5 apprentices;
The number of days required for the apprentice to complete the work alone: (4.5 + 3) * 4 = 30 days

Ask a math problem of social common sense
Three people live in the shop, one person gives 10 yuan. (30 yuan) to the second child. The second child embezzles 2 yuan. When he gives it to the boss, the boss sees that the three people don't have enough money and thinks they are very poor. One person returns 1 yuan. Finally, the boss only has 25 yuan (30-2-3). Such a person is equivalent to spending 9 yuan. The three people are equivalent to a total of 27 yuan. Plus the second child's 2 yuan, the total is 29 yuan
Please give reasons

First, look at the analysis part of this question, "finally, the boss only has 25 yuan (30-2-3). Such a person is equivalent to spending 9 yuan. Those three people are equivalent to a total of 27 yuan. Plus the 2 yuan of the waiter, the total is 29 yuan." "finally, the boss only has 25 yuan (30-2-3)" this is correct. "Such a person is equivalent to spending 9 yuan." this is

Solving mathematical problems of knowledge
3 and 20 parts 9, 50 parts 29, 7 parts 4, 10 parts 7, 16 parts 9, 2 and 32 parts 13 and 12 parts 4, 5 and 25 parts 4, which can be reduced to finite decimals, which cannot be reduced to finite decimals

9 of 3 and 20 parts, 29 of 50 parts, 7 of 10 parts, 9 of 16 parts, 1 of 2 and 32 parts, 4 of 5 and 25 parts can be reduced to finite decimal; 4 of 7 parts, 4 of 3 and 12 parts can not be reduced to finite decimal

After the opening of the expressway, the distance of the long-distance bus from a to B has been reduced by 30 kilometers, while the average speed has increased by 30 kilometers per hour, which takes only 4 hours to reach?

The distance between a and B is x km, x4-x + 307 = 30x = 320, so the distance between a and B is 320 km

Answers to 100 lessons It takes four days for one master to cooperate with three apprentices, and three days for two masters to cooperate with one apprentice. How many days does it take for the apprentice to complete the work alone?