Reason - 9th grade (14y) - math problems
- The devils
The devils weighed in hell with Dorota. They found that Dorota and the two devils weigh 250 kg together and Dorota and the four devils weigh 426 kg. All the devils weigh the same. How Much Does Dorota Weigh?
- Two rectangles 2
A square of area 36 cm2 is cut out to make two rectangles. A and B The area of area A to area B is 2 : 1 Find the dimensions of rectangles A and B.
- Time passing
6 years ago, Marcela's mother was two times older than her and two times younger than her father. When Marcela is 36, she will be twice as young as her father. How old are Marcela, her father, and mother now?
- Graduation party
There are 15 boys and 12 girls at the graduation party. Determine how many four couples can be selected.
- Long bridge
Roman walked on the bridge. When he heard the whistle, he turned and saw running Kamil at the beginning of the bridge. If he went to him, they would meet in the middle of the bridge. Roman, however, rushed and so did not want to waste time returning 150m..
- Trapezoid MO
The rectangular trapezoid ABCD with right angle at point B, |AC| = 12, |CD| = 8, diagonals are perpendicular to each other. Calculate the perimeter and area of the trapezoid.
Area of a square garden is 6/4 of triangle garden with sides 56 m, 35 m, and 35 m. How many meters of fencing need to fence a square garden?
If water flows into the pool by two inlets, fill the whole for 8 hours. The first inlet filled pool 6 hour longer than second. How long pool take to fill with two inlets separately?
Gross wage was 527 EUR including 16% bonus. How many EUR were bonuses?
Route is long 147 km and the first day first regiment went at an average speed 12 km/h and journey back 21 km/h. The second day went second regiment same route at an average speed 22 km/h there and back. Which regiment will take route longer?
A man can drink a barrel of water for 26 days, woman for 48 days. How many days will a barrel last between them?
Monkey fell in 38 meters deep well. Every day it climbs 3 meters, at night it dropped back by 2 m. On what day it gets out from the well?
One meter of the textile were discounted by 2 USD. Now 9 m of textile cost as before 8 m. Calculate the old and new price of 1 m of the textile.
In human body the blood is about 7.3% body weight. How many kilograms of blood is in the human body with weight 109 kg?
- Chickens and rabbits
In the yard were chickens and rabbits. Together they had 45 heads and 110 legs. How many chickens and how many rabbits was in the yard?
Kate thought a five-digit integer. She wrote the sum of this number and its half at the first line to the workbook. On the second line wrote a total of this number and its one fifth. On the third row she wrote a sum of this number and its one nines. Fi
From the observatory 11 m high and 24 m from the river bank, river width appears in the visual angle φ = 13°. Calculate width of the river.
- Eiffel Tower
Eiffel Tower in Paris is 300 meters high, is made of steel. Its weight is 8000 tons. How tall is the tower model made of the same material, if it weigh is 2.4 kg?
- Two cars
Two cars started against each other at the same time to journey long 293 km. First car went 41 km/h and second 41 km/h. What distance will be between this cars 20 minutes before meet?
Determine angles of the right triangle with the hypotenuse c and legs a, b, if: ?