A few simple practical problems Party A and Party B work together to make a batch of parts. It takes 12 days for Party A to do it alone, and 8 days for Party B to do it alone. After 6 days for Party B to do it alone, Party A will do the rest of the tasks alone. How many days will it take to complete the task?

A few simple practical problems Party A and Party B work together to make a batch of parts. It takes 12 days for Party A to do it alone, and 8 days for Party B to do it alone. After 6 days for Party B to do it alone, Party A will do the rest of the tasks alone. How many days will it take to complete the task?

If it takes 12 days for a to do it alone, he will finish 1 / 12 every day
B alone to complete 8 days, then he completed 1 / 8 every day
If Party B does it alone for 6 days, it completes 6 / 8, that is, 3 / 4, and there is still 1 / 4 left
1 / 4 / 1 / 12 = 3 days

1: The teacher first gives Xiaoming a piece of sugar, then gives him one seventh of the remaining sugar, and then gives Xiaohai two pieces, and then gives him one seventh of the remaining sugar. In this way, the two people get the same amount of sugar. How many pieces of sugar are there?

1+(X-1)*1/7=2+[X-1-(X-1)*1/7-2]*1/7
X=36

A simple scientific calculation problem
Under normal temperature and pressure, the number of air particles in a square box with a side length of 1cm is about 2.7 * 10 ^ 19. Suppose that the box is closed, so that only 100 million particles can run out of the small hole every second, then it will take () years to make all the air particles in the box run out
To process, good points

27000000000000000000/100000000/60/60/24/365