Themes, topics - math word problems
- Two ports
From port A on the river, the steamer started at an average speed of 12 km/h towards port B. Two hours later, another steamer departed from A at an average speed of 20 km/h. Both ships arrived in B at the same time. What is the distance between ports A an
- Where and when
The truck left Kremnica at 11:00 h at a speed of 60km/h. At 12:30 h, the passenger car started at an average speed of 80km/h. How many kilometers from Kremnica will the passenger car reach truck, and when?
- Parallels and one secant
There are two different parallel lines a, b and a line c that intersect the two parallel lines. Draw a circle that touches all lines at the same time.
- Six students
Two pupils painted the class in four hours. How long will it take for six pupils?
- Harvest time
Grandma and granddaughter Julka reap currants in 15 hours of working together. Julka herself would have currants 10 days after 6 hours of work a day. Find by what percentage the grandma's harvest time was shortened when the granddaughter was involved in
- Two villages
On the map with a scale of 1:40000 are drawn two villages actually 16 km away. What is their distance on the map?
- Mixture of nuts
The mixture of nuts should be prepared from almonds, peanuts and cashew nuts ratio 1: 2: 3 (respectively). The price of almonds is 150 CZK/kg, the price of peanuts is 140 CZK/kg and the price of cashew nuts is 180 CZK/kg. The price of the mixture is deter
5 children collect 4 liters of blueberries in 1.5 hours. a) How many minutes do 3 children take 2 liters of blueberries? b) How many liters of blueberries will be taken by 8 children in 3 hours?
- Positional energy
What velocity in km/h must a body weighing 60 kg have for its kinetic energy to be the same as its positional energy at the height 50 m?
- Floating of wood - Archimedes law
What will be the volume of the floating part of a wooden (balsa) block with a density of 200 kg/m3 and a volume of 0.02 m3 that floats in alcohol? (alcohol density is 789 kg/m3)
6l 48% alcohol, how much 52% alcohol must be added to give 50% alcohol?
The aircraft propeller rotates at an angular speed of 200 rad/s. A) What is the speed at the tip of the propeller if its distance from the axis of rotation is 1.5 m? B) What path does the aircraft travel during one revolution of the propeller at a spee
- The escalator
I run up the escalator at a constant speed in the direction of the stairs and write down the number of steps A we climbed. Then we turn around and run it at the same constant speed in the opposite direction and write down the number of steps B that I clim
- Two workers
One worker needs 40 hours to do a job, and the second would do it in 30 hours. They worked together for several hours, then the second was recalled, and the first completed the job itself in 5 hours. How many hours did they work together, and how much did
- 3 phase load
Two wattmeters are connected to measuring power in a 3 phase balanced load. Determine the total power and power factor if the two wattmeters read 1000 watts each (1) both positive and (2) second reading is negative
If the Lewis family used 648 kilowatt-hours of electricity in 12 days, how many kilowatts hours should they use in 24 days at the same rate of usage
- Voltmeter range
We have a voltmeter which in the original set measures voltage to 10V. Calculate the size of the ballast resistor for this voltmeter, if we want to measure the voltage up to 50V. Voltmeter's internal resistance is 2 kiloohm/Volt.
- Bike ride
Marek rode a bike ride. In an hour, John followed him on the same route by car, at an average speed of 72 km/h, and in 20 minutes he drove him. Will he determine the length of the way that Marek took before John caught up with him, and at what speed did M
- Three-day trip
The cyclist on three-day trip travel 30% of the total route on the first day, 3/5 of the rest on the second day and 35 km on the third day. How many kilometers did travel cyclists each day and how many?
- The tourist
The tourist traveled 78km in 3 hours. Part of the journey went on foot at 6km/h, the rest of the trip by bus at 30km/h. How long did he walk?