Let the total power consumption be x degrees: [(x-140) * 0.57+140 * 0.43]/x = 0.5.
0.57 times -79.8+60.2 = 0.5 times
0.07x= 19.6
x=280
Step by step: 140*0.43=60.2
(280- 140)*0.57=79.8
79.8+60.2= 140
2. The ratio of delivery staff to sales staff in the home appliance department of a shopping mall is 1: 8. Due to the obvious increase in the purchase of home appliances this summer, the manager of the home appliance department transferred 22 people from the sales staff to deliver the goods. Results The ratio of delivery staff to sales staff was 2: 5. How many delivery staff and sales staff are there in the home appliance department of this shopping mall?
Suppose there are x delivery people and 8X sales people.
(X+22)/(8X-22)=2/5
5*(X+22)=2*(8X-22)
5X+ 1 10 = 16X-44
1 1X= 154
X= 14
8X=8* 14= 1 12
The home appliance department of this shopping mall used to have 14 delivery staff and 1 12 sales staff.
3. Now a commodity is reduced in price 10% for promotion. In order to keep the sales amount unchanged, how many percent will the sales volume increase over the original price?
Assumption: increase by x%
90%*( 1+x%)= 1
Solution: x = 1/9
Therefore, the sales volume increased by11.11%compared with the original price.
4. The sum of the original unit prices of commodities A and B is 100 yuan. Due to market changes, a commodity decreased by 65,438+00%. B After the price adjustment of commodities rose by 5%, the sum of the unit prices of the two commodities rose by 2%. What are the original unit prices of A and B respectively?
If the original unit price of commodity A is X yuan, then B is100-X.
( 1- 10%)X+( 1+5%)( 100-X)= 100( 1+2%)
The result x = one in X=20 yuan.
100-20=80 B
5. The number of people in Workshop A is 30 less than 4/5 of Workshop B. If 10 people are transferred from Workshop B to Workshop A, then the number of people in Workshop A is 3/4 of Workshop B. Find the original number of people in each workshop.
There are x people in workshop B. According to the equality of the total number, the equation is listed as follows:
X+4/5X-30 = X- 10+3/4(X- 10)
X=250
So the number of people in Workshop A is 250*4/5-30= 170.
Description:
The left side of the equation is adjusted first, and the right side of the equation is adjusted later.
6.A rides a bike from place A to place B, and B rides a bike from place B to place A, both of which move at a constant speed, so that they can start at eight o'clock in the morning at the same time. By morning 10, they were still 36 kilometers apart, and by noon 12, they were 36 kilometers apart. How can we find the distance between a and b? (Equation)
Let the distance between a and b be x.
x-(x/4)=x-72
x=288
Answer: The distance between A and B is 288.
7. The length of car A and car B is 180m. If two trains travel relatively, it takes * * *12s from the time when the front meets the rear; If driving in the same direction, it takes 60 seconds from the front of car A to the rear of car B, and the speed remains unchanged. Find the speed of a car and b car.
The sum of the speeds of the two vehicles is [180 * 2]/12 = 30m/s.
Let the speed of a be x, then the speed of b is 30-X.
180*2=60[X-(30-X)]
X= 18
That is, the speed of car A is 18m/s and the speed of car B is12m/s..
8. Two candles with the same length, the thick one burns for 3 hours and the thin one burns for 8/3 hours. Light two candles at the same time when there is a power failure, and blow them out when a phone comes in. It is twice as thick as it is thin, and the time of power failure is found.
Suppose the blackout time is X.
Let the total length be 1, then the coarse firing is 1/3 and the fine firing is 3/8.
1-X/3=2[ 1-3X/8]
X=2. Four
Is the power failure 2. Four hours.
9. A factory produced 2300 machines this year, which was 25% higher in the first half of the year and 25% lower in the second half 15%. How many machines were produced in the second half of this year?
Solution: If X production units are set in the second half of the year, [2300-X] units will be produced in the first half of the year.
According to the meaning of the question:1-15% x+1+25% 2300-x = 2300.
Solution: 93 1
A: 93 1 set will be produced in the second half of the year.
10. A rides a bicycle from place A to place B, and B rides a bicycle from place B to place A, both of them are moving at a high speed. You should know that they set off at 8 am at the same time, and by 10 in the morning, they are still 36 kilometers apart, and by noon 12, they are 36 kilometers apart. What's the distance between a and b? ]
Let the distance between a and b be x.
x-(x/4)=x-72
x=288
A: The distance between A and B is 288 meters.
1 1. The fast horse walks 240 miles every day, and the slow horse walks 150 miles every day. Slow horse goes first 12 days. How many days can a fast horse catch up with a slow horse?
The slow horse left 150 days, the fast horse left for 240 days, and the slow horse left first 12 days, that is to say, the distance between the slow horse and the fast horse was150×12 =1800 Li before departure, and then the fast horse set off. This is the fast horse's catch-up speed in a day. The difference between the fast horse and the slow horse is 1800 Li, and the fast horse catches up with 90 Li a day, so 1800÷90=20 days is the number of days when the slow horse catches up with the fast horse.
12. It is known that five A-type machines are full of 8 boxes of products a day, and four B-type machines are full of 1 1 box of products a day, leaving 1. Each type A machine produces 1 product more than type B machine every day. How many products are there in each box?
Let's assume that there are x products in each box.
5 Type A machines: 8x+4
7 B model: 1 1x+ 1.
Because (8x+4)/5 = (11x+1)/7+1.
So: x= 12
So each box contains 12 products.
13. Father and son work in the same factory. It takes my father 30 minutes to walk from home to the factory, and my son only 20 minutes to walk this way. The father left five minutes earlier than his son. How many minutes can he catch up with his father?
Let the total length be "1", then the father's speed is 1/30, and the son's speed is 1/20.
Let the catch-up time be x.
Father left five minutes early: 1/30*5= 1/6.
x[ 1/20- 1/30]= 1/6
X= 10
That is, the time for my son to catch up is: 10 minutes.
14.200 parts need to be processed. First, A worked alone for five hours, and then worked with B for four hours before finishing the task. It is known that A processes 2 more parts per hour than B. How many parts do A and B process per hour?
Solution: Let B process (x-2) pieces per hour, then A processes X pieces per hour.
According to the total workload such as work efficiency and doubling time:
[(X-2)+X]*4+5X=200
[2X-2]*4+5X=200
8X-8+5X=200
13X=200+8
13X=208
X=208/ 13
X = 16...A.
16-2= 14 (pieces) ... b
A: Then A processes 16 pieces per hour, and B processes 14 pieces.
15. The total length of a bridge is 1000 meters. A train crosses the bridge. It takes 1 minute for the train to cross the bridge completely. The whole train stayed on the bridge for 40 seconds. Find the speed and length of the train.
1 min =60 seconds
If the length of the train is x meters, you can get it according to the meaning of the question.
The speed of the train is (1000+x)/60.
Therefore [(1000+x)/60] * 40 =1000-2x.
The solution is x= 125.
( 1000+x)/60 =( 1000+ 125)/60 = 1 125/60 = 18.75
So the train speed is 18.75 meters per second and the length is 125 meters.