Math practice for 13 year olds - page 227 of 413

Number of problems found: 8260

Price increase percentage
Easter discounts on winter goods were 20%. By what percentage does the price have to be increased retroactively to be sold again at the original price?
The Chemistry test
The Chemistry test contained eight questions, each with 3 points. Peter scored 21 points. How many percent did Peter write a test?
The wellbore
The wellbore has a tributary of 2 m³ per hour. When there is no tapping, there are a stable 28 liters of water in the well. The pump suction basket is at the bottom of the well. At 14.00, the water was pumped out at a rate of 0.5 liters every second. What
Rectangles
How many different rectangles can be made from 60 square tiles of 1 m square? Find the dimensions of these rectangles.
Cyclists and walkers
A group of tourists started at 8:00 at a speed of 4 km/h walk. At 10:30, another group started on a bike and caught up with a group of tourists at 10:50. What was the average speed of cyclists?
Two circles
Two circles with the same radius, r = 1, are given. The center of the second circle lies on the perimeter of the first. What is the area of a square inscribed in the intersection of given circles?
Two cylinders
There are two cylinders, one with oil and one with an empty oil cylinder, with no fixed value assumed infinitely. We are pumping out the oil into an empty cylinder with a radius =1 cm, height=3 cm, rate of pumping oil is 9 cubic centimeters per sec. We ar
1st drug
The first drug pack has an active ingredient ratio of L1: L2 = 2:1 The second drug pack has a ratio of active ingredients L1: L2 = 1:3 Which ratio do we have to mix the two packages so that the ratio of substances L1: L2 = 1:2?
Two integers
Two integers, a, and b, have a product of 36. What is the least possible sum of a and b?
Construct rhombus
Construct rhombus ABCD if given diagonal length | AC | = 8 cm, inscribed circle radius r = 1.5 cm
Rectangular garden
The perimeter of Peter's rectangular garden is 98 meters. The width of the garden is 60% shorter than its length. Find the dimensions of the rectangular garden in meters. Find the garden area in square meters.
Two ports
From port A on the river, the steamer started at an average 12 km/h speed 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 and B
In theatre 2
A ticket for the balcony costs x CZK, and a ticket for the auditorium costs y CZK. For the afternoon performance, 98 balcony tickets and 186 auditorium tickets were sold, earning a total of 10,970 CZK. For the evening performance, 127 balcony tickets and
Apple variete
This year, my uncle harvested 350 kg of apples, including 105 kilograms of Ontario and the rest of Jonathan's apples. Determine the percentage of the Jonathan apples.
Art school
Every fifth pupil of 9A class goes to art school. How many percent of pupils in class 9A go to art school?
Postage increase percentage
Postage for packages has increased to 7/5 of the original price. What percentage has the postage for packages increased?
Ski equipment price
Petr found out that he would save CZK 1,680 with a 24% discount when selling winter goods. Calculate the original price of ski equipment.
Kinetic energy
A car traveling at a speed of 25 km/h increased the speed to a) 75 km/h b) 100 km/h when exiting the highway. How many times has its kinetic energy increased?
Hammer fall height
From what height does a hammer weighing 200 kg fall if its initial potential gravity was 6 kJ?
The elevator
The elevator car weighing 400 kg rises from the third to the fifth floor. By what value will the potential gravitational energy of the cabin increase? What useful work will the elevator motor do? The height of one floor is 5 m.

Do you have unsolved math question and you need help? Ask a question, and we will try to solve it. We solve math question.