Math practice for 13 year olds - page 255 of 424

Number of problems found: 8480

Simple equation 6
Solve the equation with one variable: X/2+X/3+X/4=X+4
Diameter 7591
The pedal wheel on a bicycle has 28 teeth. The gear wheel on the rear wheel has 8 teeth. How many times does the rear wheel turn if we step on both feet 112 times? How many meters can we travel with it at least, and how much more if the rear wheel has a d
Municipal 7590
One m³ of air weighs 13/10 kg, and the same volume of municipal gas is 4/5 kg. How many times is a gas lighter than air?
One trapezium
One trapezium has AB=24M, BC=36M, CD=80M, DA=80M long sides. Find the area.
Inequality 7581
How many prime numbers are the inequality solutions: x / 3> x - 8?
Iron density
Calculate the weight of a 2 m long rail pipe with an internal diameter of 10 cm and a wall thickness of 3 mm. The iron density is p = 7.8 g/cm³.
Perfect cubes
Suppose a number is chosen at random from the set (0,1,2,3,. .. ,202). What is the probability that the number is a perfect cube?
Simultaneously 7571
A pedestrian and a cyclist left the town of S simultaneously but in the opposite direction. Pedestrian at 4.4 km/h, cyclist at 18 km/h. How far apart are they after 1 hour and 42 minutes?
Pedestrian 7570
A pedestrian left town S at a speed of 4.2 km/h. After 1 hour and 10 minutes, a cyclist left the same city and in the same direction at a speed of 18 km/h. After how many minutes does the cyclist catch up with the pedestrian, and how far from town S?
Another 7568
A cyclist leaves town A, 84 km from town B, and 2 hours later, another cyclist goes from town B to town A at the same average speed of 14 km/h. How far from city B will they fight?
Trip to a city
Lin wants to save $75 for a trip to the city. If she has saved $37.50 so far, what percentage of her goal has she saved? What percentage remains?
Parallelogram
Rhomboid (parallelogram) has a longer side of 50 cm long. The size of its one height is four times the size of its second height. Calculate the length of the shorter side of this rhomboid in centimeters.
Octagonal tank
The tank has the shape of a regular octagonal prism without an upper base. The base edge has a = 3m, and the side edge b = 6m. How much metal sheet is needed to build the tank? Do not think about losses or sheet thickness.
21-kilometer 7555
A tourist moving at the same pace completes a 21-kilometer hike in 4 hours, taking a 30-minute break. Calculate the average speed of tourists.
Direction 7554
A freight train departs from one station at an average speed of 36 km/h. 2 hours later, personal pressure leaves in the same direction at an average speed of 48 km/h. After how many hours will the passenger train catch up with the freight train?
Consecutive 7551
Determine the sum of three consecutive natural numbers such that the sum of the first and third numbers is 368.
Difference 7548
The difference between every two adjacent numbers equals three in a series of four numbers. The sum of these numbers is 60. Specify these numbers.
Feet to miles
A student runs 2640 feet. If the student runs an additional 7920 feet, how many total miles does the student run?
KLMN trapezoid
The KLMN trapezoid has bases KL 40cm and MN 16cm. On the KL base is point P. The segment NP divides the trapezoid into units with the same area. What is the distance of point P from point K?
Cutting paper
Divide a rectangular paper with dimensions 220mm and 308mm into squares of the same size so that they are as large as possible. Specify the length of the side of the square.

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