2. A project was completed by Party A alone, and it took Party B 3 days to complete it. Now Party A and Party B have cooperated for two days, and the rest of the project will be completed by Party B within the specified time limit. How many days is the prescribed time limit?
1 Solve the equation
2/x+ 10/(x+ 16)= 12/(x+8)
Making y = x+8 can simplify the calculation.
Y = 12，X = 4。
That is, the speed of human walking is 4 km/h.
Let the quantities of work be M, A and B, and the specified time limit is X days.
There is m = ax
m=b(x+3)
m=2(a+b)+(x-2)b
The solution is a=3/2b, x=6, and the prescribed time limit is 6 days.
A ship is heading for a port at normal speed. When it completed 2/3 of the distance, the machine broke down and the speed was reduced by 5 nautical miles per hour until it docked at this port. The time it takes is the same as the time it takes to complete the whole journey at a speed of 3 nautical miles per hour. Find out the normal speed of this ship.
?
Distance s normal speed v
Twice equal: (2/3) * s/v+(1/3) * s/(v-5) = s/(v-3).
Eliminating s to solve fractional equation: V=90/42
4. The distance between Party A and Party B is160km. Three hours after a long-distance bus leaves from Party A, another bus also leaves from Party A, and as a result, the bus arrives at Party B 20 minutes later than the long-distance bus. It is known that the speed of the bus is three times that of the long-distance bus. What is the speed of the two cars?
Let the speed of the coach be x and the speed of the car be 3x.
Then it is 160/x (the time of long-distance bus)-160/3x (the time of bus) = 8/3 (the unit is minutes, because the time of long-distance bus driving is +3 hours -20 minutes).
Solve x = 40km/h.
So the speed is120km/h.
The plan has been changed because 7200 tents need to be produced. The total output value is required to be 20% higher than the original plan, and 720 tents are actually produced every day. How many tents are actually produced every day?
Solution: Assuming that X tents are actually produced every day, it can be obtained according to the meaning of the question.
7200/(x-720)-7200 *( 1+20%)/x = 4
The solution is x= 1440.
That is, the actual production of 1440 tents per day.
6. Two kinds of goods with the same weight, the value is 900 yuan and 1500 yuan respectively. It is known that the value of one kind of goods per kilogram is less than that of the second kind of goods, 300 yuan. Find the value of each kilogram of these two commodities respectively.
7. The bus takes 480 kilometers of expressway from A to B and 600 kilometers of ordinary highway from B to A. It is also known that the average speed on the expressway is 45Km kilometers faster than that on the ordinary highway, and the time from the expressway to the second place is half that of the ordinary highway to the second place. Find the time required for the bus to travel from the expressway to the second place.
8. The distance from A to B is 15km. A rides a bike from a to b first. After 40 minutes, B rides from A and arrives at the same time. Given that the speed of B is three times that of A, find the speed of two cars.
9. A tractor A plowed half of a piece of land in 4 days, and a tractor B plowed the other half in 1 day. B How many days does it take a tractor to plow the field alone?
10, the time required for A to manufacture 90 parts is the same as that required for B to manufacture 120 parts. It is known that A and B manufacture 35 machine parts per hour. Find out how many parts A and B produce per hour.