-
Anonymous users2024-02-061. Dad's 4 km time is 8 minutes less than Xiao Ming's 4 km time;
Dad's 8+4 km takes the same time as Xiao Ming's 8-4 minutes.
Therefore, the time taken by Dad is Xiao Ming's (8+4) (8-4)=1 3 Xiao Ming's time for 4 kilometers: 8 (1-1 3)=12 (minutes) Xiao Ming's time for 8 kilometers: 12 2=24 (minutes) At this time, it is 8:32.
2. Add 2 machines at the specified time to complete: 1 (7 8) = 8 7 total machines: 2 (8 7-1) = 14 (sets).
One machine is required to complete this project: 2 3 (1 12-1 14) = 56 (hours).
-
Anonymous users2024-02-05Solution: Dad's speed is several times that of Xiao Ming: (4+8) 4=3 (times) The time required for Dad to walk 4 kilometers: 8 (3-1)=4 (minutes) Dad's speed: 4 4=1 (kilometers min).
A: It was 8:32 a.m
Number of original units: 2 (8 7-1) = 14 units.
14-2=12 units.
The present is the original time: 14 12 = 7 6
It takes 14 4 = 56 hours to complete the project by one machine.
-
Anonymous users2024-02-04The answer to the first question is 8:40
Let Xiao Ming walk x kilometers every minute, and Dad will walk y kilometers every minute. Then 4 x - 4 y = 8 8 x - 12 y = 8, and the solution is x= y=
8 x = 32 minutes 8:08 after 32 minutes is equal to 8:40 Question 2: If there are expected x machines and the time used is y, then x*y=(x+2)*(7y 8)=(x-2)*(2 3 +y).
x=14 y=4 14*4=56, the answer is 56 hours.
-
Anonymous users2024-02-03There will be 20 people who subscribe to C magazines.
The number of people who order all three copies is x, x = 64 - those who order only one book - those who order only two copies .........1) And because: 10 + x + people who only subscribe to A magazine = 28
12 + x + people who only subscribe to b magazine = 41
12 + x + people who only subscribe to C magazine = 20
So: 3x+ (only A magazine + B only + C only) = 55, i.e.: 3x+ people who only subscribe to one magazine = 55 .........2) And because: x+ people who only subscribe to two kinds of magazines AB = 10
x + people who subscribe to only two types of BC magazines = 12
X + people who subscribe to only AC two magazines = 12
So 3x+ (only two magazines for ab + two magazines for bc + two magazines for ac) = 34
i.e.: 3x + people who subscribe to only two magazines = 34 .........3) Substituting Eq. (2) and (3) into Eq. (1) obtains.
x=64-(55-3x)-(34-3x)
Get x = 5 Question 2 75 + 60 = 135
Fill an average of 5 boxes, and finally have an extra one, indicating that the single digit is 1 or 6 If you should use 6 boxes, and finally there are four more, it means that the single digit is an even number, so the single digit is 6 hundred digits, the single digit is 6, and the single digit is 6, and it is between 150-200. >>>More
1. The picture is not well drawn, the blank part of the midpoint, the three intersection points are the center of three circles, and it is not difficult to see that a small shadow can be calculated according to an equilateral triangle with a side length of 5 cm corresponding to the fan, that is to say, the area of the shadow part can actually be seen as three equilateral fans with a side length of 5 cm. >>>More
China's total water resources are 2.8 trillion cubic meters, and the current water resources consumption has accounted for 1.5 percent of the total, and its development and utilization has exceeded that of any country in the world. China's total groundwater resources are 870 billion cubic meters, of which 200 billion cubic meters can be exploited and 88 billion cubic meters have been exploited. All in all, China is a water-scarce country, with per capita water resources only 1 4 per capita in the world, 1 7 in the former Soviet Union, and 1 3 in the United States. >>>More
1. The gymnastics team queues up, if you add a line, each row is 40 people, and the reduced line is 50 people per line, ask how many lines are there? >>>More
Travel through the long tunnel of time and space for 30 years with a flick of your fingers. >>>More