Math practice for 13 year olds - page 105 of 428

Number of problems found: 8558

Equilateral cone
The axial section of the cone is an equilateral triangle with a side of 12 cm. Surface and volume calculation.
Three-digit number creation
From the number 5,4,0,7,8, create three-digit numbers, so they do not repeat and solve the problem by calculation.
Tree shadow length
How long is the shadow of a tree 7.6 m high, and the shadow of a 190 cm high road sign is 3.3 m long?
Track ascent meters
How many meters will the track ascend if it is 200 kilometers long and the ascent is 7 per mille?
Peter crown ratio
Peter has only two crowns in the treasury and can divide them both in a ratio of 4:5 and in a ratio of 4:7. How many crowns does Peter have in the money box if the amount saved is less than 300 CZK?
Car's mileage
A car owner has her tank filled and notices that the odometer reads 14,368.7 kilometers. After a trip in the country, it takes 34.5 liters to fill the tank, and the odometer reads 14,651.6. How many kilometers per liter is this car getting?
Four numbers
I am a four-digit number, no zeros, in which the first number is five times the last, the second is four more than the first and three times the third, and the third is two more than the last and two less than the first.
Buses A and B
Bus A leaves Worcester at 08:00 and travels north along the N1 at 50 km/h. Bus B leaves Worcester at 10:00 along the same route at 70 km/h. At what time will bus B pass bus A?
Centi-year deca-month comparison
How many minutes is the centi-year longer / shorter than a deca-month? The year is 365 days, and the month is 30 days.
Unknown permille
75 per mille of an unknown number equals 60. What is an unknown number?
A flagpole
A flagpole is leaning at an angle of 107° with the ground. A string fastened to the top of the flagpole is holding up the pole. The string makes an angle of 38° with the ground, and the flagpole is 8 m long. What is the length of the string?
Pump diesel liters
Three identical pumps fill 50,400 liters of diesel into the tank in 7 hours. How much more (less) diesel will they pump if we add two more pumps, and they will all work for 4 hours?
Seed drills
The tractor driver connected two seed drills behind the tractor and sowed 7 ha of grain in 5 hours. How many hectares did he plant in 8 hours the next day if he connected three seed drills?
20 balls
20 colored balls in a bag: Four red Seven green Nine yellow What is the probability of picking a yellow ball?
Beijing Tokyo scale
The map shows the cities of Beijing and Tokyo at a distance of 5.1 cm. Their actual air distance is 2040 km. What is the scale of the map?
Four-digit number creation
How many four-digit numbers can we assemble from the digits 2, 6, 3, 5, 1, and 9 if the numerals in the number cannot be repeated?
Shirt short combinations
Dušan has 8 T-shirts and three pairs of shorts in his closet. How many ways can he dress for school?
A person
A person buys 10 kg of commodity A at a rate of 2 kg per dollar, 20 kg of commodity b at a rate of 5 kilograms per dollar, and 30 kg of commodity C at a rate of 10 kg per dollar. Find the average price of kg per dollar.
Divide line segment
Find the point P on line segment AB, such that |AP| = r |AB|. Coordinates of endpoints: A = (−2, 0, 1), B = (10, 8, 5), ratio r = 1/4.
Railway descent permille
Calculate the permille descent of the railway line in the section of 7.2 km by 21.6 m.

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