Maths practice for 12-year-olds - page 265 of 307
Number of problems found: 6135
- Gears
The gearing fits the wheel with 20 teeth to the wheel with 36 teeth. Before the machine is started, personnel mark the teeth of the smaller wheel and the opposite of the larger wheel. How many times after starting the machine wheels turning that painted t - Saving
Paul saves 155Kč in 46 2 Kc and 5Kc coins. How much saved 2Kc and 5Kc coins? - 6 regular polygon
A regular six-sided polygon has a side 5 cm long. Calculate its area. Compare how many more cm² (square centimeters) has a circle inscribed the 6-gon. - What percentage
What percentage is 12 km out of 80 km?
- Floor
The rectangular floor of the living room has a length of 5.4 meters and a circumference of 17.2 meters. What is its width? - Bob and Bobek
Bobek runs from the hat at an average speed of 12 km/h at 10:20. At what time must Bob run out at a speed of 18 km/h to catch him 9 kilometers from the hat? - Dwarfs
Four dwarfs would prepare firewood for Snow White in 580 minutes. After an hour and a half, they recruited friends and finished preparing the wood for 280 minutes. How many dwarfs do they recruit? - Number
I think the number. If I add to its third seven, I get the same as when to its quarter add 8. What is the number? - Two cars 2
Two cars started from two positions 87 km distant at the same time in opposite directions at speeds of 81 km/h and 75 km/h. What was the distance between them after 2 hours and 50 minutes of driving?
- Pedestrian and the cyclist
Pedestrians and cyclists went against each from the two cities that are distant 40 km. The pedestrian started 30 minutes before the cyclist and walked at an average speed of 5 km/h. What speed went the cyclist when met after 120 minutes from the start of - Beer permille
In the 5 kg of the blood of an adult human after three 10° beers consumed in a short time is 6.6 g of alcohol. How much is it per mille? - Passenger car and truck From Kutna Hora left at 11:00 clock a truck at 60 km/h. At 12:30, behind him started the passenger car at an average speed of 80 km/h. At what time and how far from Kutna Hora overtake a passenger car truck?
- Car - road
The car started at 11:40, traveling 54 km/h between A and B, and arrived at 12:20. Find the distance between A and B. - Technical 2617
Pupils work in groups of two on technical work in the school to make a birdhouse. If Tomáš worked alone, he would make the booth in 4 hours. Richard would do it in 2 hours. If they work together, how many hours will it take them to complete it?
- Vegetable 2616
Danka was supposed to dig a vegetable patch in the garden. She would have carved it in 1.5 hours if she had worked alone. If her sister Hanka were to cut it alone, she would carve it in 0.75 hours. How long would it take them to weed the garden together? - Boots
Master shoemaker has three apprentices. First, do one pair of boots for two days, second for one day, and third for 1.5 days. How long would it take to make a couple of boots if they worked together? - O'clock 2614
One pump fills the school pool in 15 hours. The school bought another pump that would fill the pool in 10 hours. What is the latest time to start filling the pool if they want to have it filled at eight o'clock in the morning and use both pumps? - Classmate 2613
Juro didn't have a watch, so he asked a classmate for the exact time. Simon looked at the clock and said: "If my watch were 22 minutes late, it would be 11:54. But it's not that much because my watch doesn't miss; it goes 22 minutes ahead". What time was - Forgets 2612
It happens to Dorothy that when filling the bath with water, she forgets to put a plug in the drain. The bath would fill up in 20 minutes if the drain were blocked. A full tub would be emptied through the drain in 30 minutes. How long will it take Dorothy
1. Determine a number with the same result if we multiply it by ten as if we add 10 to it. 2. Věra is twice as old today as her sister Jitka. In five years, Jitka will be only 1/3 years younger than Věra. How old are Věra and Jitka today? 3. Find the pairDo you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.
