I am anxious to ask for 2 logical reasoning questions, if anyone knows, please let me know the quest

From the 1st floor to the 5th floor, it takes 15 seconds to ascend 4 floors, and the time taken for each floor is 15 4

From the 1st floor to the 25th floor, 24 floors are raised, so the total time spent: 15 4 * 24 = 90 seconds.

2+5+8+2 should be 17 minutes.

Suppose 4 people are called A B C D, A is 1 minute, B is 2 minutes, C is 5 minutes, and D is 8 minutes.

Because there was only one flashlight, someone had to bring it back every time I went over.

I want the shortest time, so the person who brings back the flashlight can only choose the fastest person, which is A.

So A has to take the flashlight back every time he walks with someone else.

Two people cross the bridge together, the speed is the slower, so the remaining 3 people cross the bridge for less than 2 + 5 + 8 = 15 minutes.

Then add the time A went back to pick up someone else, and picked it up 2 times, so it was 15 + 2 = 17 minutes.

17 minutes

Let people who cross the bridge for only 1 minute go back and forth, and bring back the flashlight.

73 people The title is very clear.

73 people The title is very clear.

There are 24 people in total.

The presence of men and women precludes the possibility that all participants were girls. So the boys and girls are spaced apart, and they are in a circle, and the number of men and women must be the same.

If there are 12 women, then there must be 12 men, for a total of 24.

According to condition 4, we can know that the shops are closed on the first day and the sixth day, so all three stores are open only on the seventh day.

According to condition 3, the department store must be open on the first day, otherwise, it will be open for three consecutive days and will not be eligible for condition 3. In the same way, banks must be open on the first day, and supermarkets must be open on the third day.

Make a ** list and fill in the table with the above derivation results, as shown in the figure below

The supermarket needs to be open for two more days in the third day, if it is or , then add the 7th day of known business and open for three consecutive days, which does not meet the condition 3, so it can only be open on the first day and closed on the 6th day, fill in ** to get the following figure:

There is no need to deduce later, as you can see from the table above, there are shops open every day except the second day, so the second day must be a Sunday (all stores are closed). Therefore, the 7th day when all stores are open is Friday.

You can only be in the middle three squares. Take one for each. A total of 27 books were taken out. The rest of the books are distributed in the shelves like this: