Math practice for 13 year olds - page 305 of 422
Number of problems found: 8424
- Mr and Mrs
Mr. Calda and Mrs. Cald have a total of 139 years. How many years have when we known that Mr. Calda is nine years older than Mrs. Cald? - The tram
The tram is moving with acceleration a = 0.3m/s2. How long will it pass the first meter of the track? How long does it take 10 meters? What is its speed at the end of the 10-meter track? - Pumps 4912
A pool with one pump fills in 14 hours and the other in 15 hours. How long will the pool fill when both pumps are used? - Driver
The driver of the supply car reckoned that at the average speed of 72 km/h arrived at the warehouse for 1 1/4 hours. After 30 km, however, he unintentionally drove to the gas station and had ten minutes delay. At what average speed would you have to go th - Trapezoid 4908
Trapezoid ABCD with bases AB = a, CD = c has height v. The point S is the center of the arm BC. Prove that the area of the ASD triangle is equal to half the area of the ABCD trapezoid. - Immediately 4906
It is Monday at 10 a.m. Luboš has returned from the doctor, who prescribed him tablets: he will take the first one immediately, the next two days he will take them after six hours, and the rest after eight hours. When will Luboš collect all the tablets if - Deviation 4905
The flower bed has the shape of a regular 4-sided pyramid. The edge of the lower plinth is 10 m, and the upper plinth is 9 m. The deviation of the side wall from the base is 45 degrees. How many plantings should be purchased if 90 are needed to plant 1 sq - Painting
To paint the pool with dimensions: 2 meters depth, 3m x 4m we bought paint to 50 meters square. How much "paint" will be wasted? - Increased 4898
The price of flour increased three times in a row by 10% each time. The shop then reduced it by 30%. Now the price of flour is 5.60 CZK. What was the original price? - Right triangle trigonometrics
Calculate the size of the remaining sides and angles of a right triangle ABC if it is given: b = 10 cm; c = 20 cm; angle alpha = 60°, and the angle beta = 30° (use the Pythagorean theorem and functions sine, cosine, tangent, cotangent) - Forces on earth directions
A force of 60 N [North] and 80 N [East] is exerted on an object weight of 10 kg. What is the acceleration of the object? - Volume increase How much percent will increase in the pool 50 m, width 15m if the level rises from 1m to 150cm?
- Hydrostatic force
What is the hydrostatic force applied to an area of 30 cm² in the water at a depth of 20 m? (Water density is 1000 kg/m3) - Sales of products
For 80 pieces of two quality products, the total sales are 175 Eur. Suppose the first quality product was sold for n EUR per piece (n natural number) and the second quality product after 2 EUR per piece. How many pieces of the first quality were sold? - Sphere radius
The surface of the sphere is 60 cm square. Calculate its radius; result round to tenth of cm. - Championships 4886
The pool had to be filled before the World Championships. The first pump would fill in 12 hours, the second in 15 hours, and if all three pumps were started simultaneously, they would fill the pool in 4 hours. How long would the pool be filled with only t - Two-digit 4883 Dad had 33 bills. One hundred crowns, two hundred and five hundred. A two-digit number gave the number of each species. How many did he have if he had a total of 9100 CZK?
- Three-digit 4882
There were 301 postage stamps in the desk drawer. They were stamps for 2, 3, and 5 crowns. The number of each species can be written as a three-digit number. The total price of all stamps is CZK 1,003. How many stamps were there? - Individual 4881
There are 32 rooms in the hostel. Some have double beds, others have four beds and the rest have 7 beds. There are a total of 139 beds in the hostel. How many are there if a two-digit number gives the numbers of individual species? - Five-crowns 4879
Eva had seven coins. Crowns, two-crowns, and five-crowns. At least two of each. How many did she have if she could buy three packs of gum for six crowns?
Do you have unsolved math question and you need help? Ask a question, and we will try to solve it. We solve math question.
