Solution: 35/(1-5/60) = 35/(1-kloc-0/12) = 35/(11/.
The clock in the square is now 7 o'clock sharp. At 38 and (2/ 1 1) minutes, the hour hand and the minute hand coincide for the first time.
2, the number of a commodity is a three-digit number, there are five three-digit numbers 874, 765, 123, 364, 925, each number is the same as the number of the commodity, so the number of the commodity is ().
Solution: Using the exclusion method, if the unit is 5, none of the remaining 3 digits are of the same sign, and 10 or 100 with the same sign can only take 2 digits at most, then there must be 1 digit that is inconsistent with the meaning of the question, so you can only choose 4 for excluding 5 and 2 for excluding 10. Similarly, there are only 765 bits left, and 7 is selected from 100 bits. This number is 724.
3. It takes 3 days for a boat to travel from City A to City B, 4 days for a boat to travel from City B to City A, and () days for an unpowered raft to drift from City A to City B. ..
Solution:1÷ [(1/3-1/4) ÷ 2] = 24 (days)
4. 1998 8/9+ 1999 8/9+2000 8/9+200 1 8/9+2002 8/9+5/9.
Solution:1998 8/9+1999 8/9+2000 8/9+2006 5438+0 8/9+2002 8/9+5/9.
= 1999+2000+200 1+2002+2003
=200 1*5
= 10005
5. In Xiaoming's yard, there is a square utility room beside a 600 cm foundation. Xiao Ming tied the dog to a corner of the utility room with a rope 14 meters long. Now the dog starts from point A, tightens the rope and runs clockwise. How many meters can it run?
Solution: There are actually three different circles, one is a semicircle with a radius of 14m, the other is a quarter circle with a radius of 8m, and the other is a quarter circle with a radius of 2m.
*2*π* 14+? *2π*8+? *2π*2= 19π
6. After the business hall of a bank opened, customers came to handle business one after another. If only one window is opened, the hall will be full of customers after 15 minutes; If you open two windows, customers can fill the hall in 30 minutes. Assuming that the number of customers who come to handle business every minute remains the same, and each customer has the same time to handle business, how many windows does the bank have to open at least to ensure that customers are on call?
Solution: There must be at least three.
If you open a window, 15 minutes can fill the hall, which means 15 minutes can fill a hall. If one more window is opened, customers can fill two halls in 30 minutes. If two windows are opened, customers can fill the hall in 30 minutes, that is, one hall is full, which means that one window can handle as many customers as one hall in 30 minutes.
Therefore, if there are still so many customers standing in a hall after 30 minutes, and a window can handle so many customers within 30 minutes, then opening a window at the beginning of the business can handle these customers' business in time without queuing.
So the second bank should open at least three windows.
7. A, B and C villages jointly build a road, and the ratio of roads built by the three villages is 8:7:5. Now the three villages are required to send labor according to the repaired road. Due to special reasons, village C didn't send labor, but it had to pay 1350 yuan to villages A and B, so that village A sent 60 people and village B sent 40 people. Q: How much should each village get?
Solution: The total number of people is:
60+40= 100 people
The number of factions in Sancun is:
A: 100*8/(8+7+5)=40 people.
B: 100*7/(8+7+5)=35 people.
C: 100*5/(8+7+5)=25 people.
Many factions in one village:
60-40=20 people
Multi-faction in village B:
40-35 years old =5 people
The proportion of money in each village is:
20:5=4: 1
Therefore, a village is worth:
1350 * 4/(4+1) =1080 yuan
Village b is worth:
1350 *1/(4+1) = 270 yuan.
8. There is a container with a cylinder at the bottom and a cone at the top. The cylinder height is 10 cm, the cone height is 6 cm, and the water depth in the container is 7 cm. When the container is inverted, what is the height from the tip of the cone to the liquid level?
Solution: Because the volume of a cone with equal base and equal height is 1/3 of the volume of a cylinder.
Therefore, the volume of a cone with a height of 6 cm is equivalent to that of a cylinder, and the height is 6× 1/3=2 cm.
The height of the remaining cylinder is 7-2 = 5cm.
When the container is inverted, the height from the cone tip to the liquid level is 6+5= 1 1 cm.
9. As shown in the figure, the areas of the two shaded parts are respectively S 1, S2, S1-S2 = 3cm2. Find the radius of this circle.
Solution: s 1-s2=3cm①.
S 1+s (white part) =πR? /4? ②
S2+s (white part = 3× 8 = 24cm3)
∵②-③=①
∴πR？ =27×4? π=3
∴R=6㎝
The radius of the circle in the figure is (6) cm.
10, SF transportation team has delivered 10000 porcelain bowls, and the freight is 1.5 yuan has 100 bowls. 1 The bowl was damaged, and the freight was not paid. 0.2 yuan, after completing the transportation task, the transportation team got the freight 146.56 yuan. How many bowls were damaged in transit?
Solution:? Set the damaged bowl x? Only.
( 1.5/ 100)x( 10000-x)-0.2x = 146.56？
x= 16