Because the bus travels 42 kilometers more than the truck in 3 hours, and 1 hour travels 42/3= 14 kilometers more than the truck, the speed of the bus is 14/(7-5)*7=49 kilometers per hour, and the distance between Party A and Party B is 49×3×2=245 kilometers.
2. A basket of apples sold 1, and then sold 8 kilograms. At this time, the ratio of surplus to sale is 2: 65,438+0. How many kilograms is this basket of apples?
Because it was sold twice1(2+1) =1/3, and the second time it was sold1/3-1/5 =1/5.
3. An express train and a local train travel in the opposite direction from Nanjing and Yangzhou respectively at the same time, and meet 3 kilometers away from the midpoint after 2 hours. It is known that the average speed of the express train is 75 kilometers per hour, and how many kilometers is the average speed of the local train?
When we met, the express train traveled 3×2=6 kilometers more than the local train, so the express train traveled 6/2=3 kilometers more than the local train every hour, so the local train traveled 75-3=72 kilometers per hour on average.
4. To buy the same car, Uncle Zhang has to pay 7% more in installments, and Uncle Li enjoys a 15% discount in cash. Uncle Zhang pays 7200 yuan more than uncle Li. What is the original price of this car?
7200/( 1+7%-95%)=60000 yuan.
5. Two thirds of a number is equal to three fifths of b number, the sum of a number and b number is 38, and a number is (18).
The ratio of number A to number B is (3/5)/(2/3)=9/ 10, and the number A is: 38*9/( 10+9)= 18.
6. A cylinder with a length of 4 decimeters, the total surface area obtained by cutting it into 8 small cylinders is more than that obtained by cutting it into 5 small cylinders 180 square centimeters. The original volume of a cylinder is (1200) cubic centimeter.
Cut into 8 small cylinders, the surface area increases by 14, and cut into 5 small cylinders, the surface area increases by 8 bottom areas, so the bottom area is: 180/( 14-8)=30 cm2, and the original cylinder volume is: 30× 4× 10 =.
7. When the height of a cuboid is reduced by 2cm, its surface area is reduced by 48cm2 and it becomes a cube. The volume of a cuboid is 288 cubic centimeters.
The part with reduced surface area is lateral area with reduced height of 2 cm, and lateral area = bottom circumference × height.
So the perimeter of the bottom surface is 48/2 = 24cm, the side length of the bottom surface is 24/4 = 6cm, and the volume of the cuboid is 6× 6× (6+2) = 288cm3.
( 1/ 15+3/49)* 15-45/49
= 1/ 15* 15+3/49* 15-45/49
= 1+45/49-45/49
= 1
8. Production of a batch of parts, originally planned to produce 80 pieces per day, can be completed within the scheduled time. Actually, 100 pieces were produced every day, and the result was completed 6 days ahead of schedule. How many parts are there in this batch?
Production of 100 units per day, according to the planned days, production of 100×6=600 units per day, 100-80=20 units, so the planned days are 600/20=30 days.
So this batch has 80×30=2400 parts.
9. The gym bought 75 balls, of which basketball is twice as many as football, and volleyball is three more than football. How many balls do these three kinds have?
There are: (75-3)/(2+1+1) =18 football, 18×2=36 basketball, 18+3=2 1 volleyball.
10. The surface area of the cuboid block is 46.9 square decimeter, the bottom area is 16.25 square decimeter, and the bottom circumference is 18 decimeter. How many cubic decimeters is the volume of this cuboid?
Surface area of cuboid = lateral area+bottom area ×2.
Transverse area = bottom circumference × height.
Remember these two formulas @! @@
Height of cuboid: (46.9-16.25× 2)/18 = 0.8 decimeter.
Volume of cuboid: 16.25×0.8= 13 cubic decimeter.
1 1. Students take part in the Mathematical Olympiad. The number of boys is 1 1 more than the total number, and the number of girls is 1. How many people took part in the competition?
1 1/20 * 1/4= 1 1/80
100* 1/4=25
That is, the number of girls is 25 more than the total number 1 1/80.
Therefore, * * * participants in the competition are: (100+25)/(1-kloc-0//20-1/80) = 400 people/kloc. The number of female singers who didn't win the prize accounted for 1 of the total number of female singers, 16. Male singers didn't win the prize, but the number of male singers who won the prize was the same. Q: How many male singers took part in the competition?
The female singer is: (407-16)/(1+8/9) = 207.
Male singer: 407-207=200.
12. Both the master and the apprentice * * * processed 170 parts, and the number of parts processed by the master is more than that processed by the apprentice 1/3, so how many parts did the apprentice * * * process?
After 10 * 4 = 40 is added to the number of parts processed by the apprentice, 1/3 of the number of parts processed by the master is exactly equal to 1/4 of the number of parts processed by the apprentice. In this way, the total number of parts is 3+4 = 7, the master processes 3 and the apprentice processes 4.
13. Both a cart and a car drive from A to B, and the speed of the cart is 80% of that of the car. It is known that the big car started 17 minutes earlier than the small car, but it stopped at the midpoint of the two places for 5 minutes before continuing to B. However, after the small car started, it went straight to the second place without stopping. Finally, the bus came second before the bus. It is also known that the bus departs from the first place at 10 in the morning. So when did the bus catch up with the bus in the morning?
This topic is similar to question 8. But it's more complicated than question 8!
The bus is more than the car 17-5+4 = 16 minutes.
Therefore, it takes 16 ÷ (1-80%) = 80 minutes to complete the bus journey.
It takes 80× 80% = 64 minutes for the car to complete the whole journey.
Since the car has stopped at the midpoint, we have to discuss whether we can catch up at the midpoint.
The bus will reach the midpoint at 80 ÷ 2 = 40 minutes after departure, and leave at 40+5 = 45 minutes after departure.
The bus starts after 17 minutes, and the bus keeps running 17+64 ÷ 2 = 49 minutes.
It means that when the car reaches the midpoint, the cart has already started again. And then get caught in the second half of the road.
As neither of them had a rest, the bus arrived four minutes earlier than the bus.
Then the catch-up time is 4 ÷ (1-80%) × 80% = 16 minutes ago.
So, after the bus leaves, 17+64- 16 = 65 minutes.
So the time at this time is 1 1: 05.
14. For a manuscript, it takes 14 hours for Party A to type alone, and 20 hours for Party B to type alone. If Party A types 1 hour first, then Party B types 1 hour instead of Party A, and then Party A types 1 hour instead of Party B. .................................................................
Party A completes114 and Party B completes 1/20 every hour, and the sum of their work efficiency is:114+1/20 =17//.
Because1/(17/140) = 8 (hours) ... 1/35, that is, after two people play for 8 hours each, there is 1/35 left. This part of the work will be completed by Party A, which requires:
(1/35)/(114) = 2/5 hours = 0.4 hours.
Therefore, when the manuscript is finished, it will take them * * * 8 * 2+0.4 = 16.4 hours.
1There are 3 yellow balloons in 5.2 yuan and 2 flower balloons in 3 yuan. The school * * * bought 32 balloons, 4 of which were fewer than yellow balloons. What balloons do schools spend more money on?
Number of yellow balloons: (32+4)/2 = 18, number of flower balloons: (32-4)/2 =14;
Total price of yellow balloon: (18/3) * 2 = 12 yuan, and total price of flower balloon: (14/2) * 3 = 2 1 yuan.
16. The sailing speed is 60m/min. In a river with a current speed of 20 meters per minute, the ship travels from the upstream port to the downstream place, and then returns to its original place. * * * How many meters did the ship walk from the upstream port to the downstream in 3 hours and 30 minutes?
Ship downstream speed: 60+20 = 80m/min, ship downstream speed: 60-20 = 40m/min.
Because the ratio of downlink speed to uplink speed is 2: 1, the time ratio of downlink speed to uplink speed is 1: 2.
The time from the upstream port to the downstream location is:
3 hours and 30 minutes *1/(1+2) =1hour 10 minutes = 7/6 hours. (7/6 hours = 70 minutes)
The distance from the upstream port to the downstream position is:
80 * 7/6 = 280/3km。 (80×70=5600)