Problems for 9th grade
School kitchen bought 36kg apples for 12 kc/kg. How many kilograms of apples 1/4 cheaper can they buy for the same money?
Imagine that a unit of air at a temperature of 25°C rises up a mountain range that is 3,000 meters high on the windward side and which descends to 1,200 meters on the leeward side, assuming that the air will remain dry what will its temperature when it cro
- Insect spraying
In 600 ml of spraying is 5 ml of an active ingredient. How much is it per miles?
- Fruit tea
Tea contains 7% of fruit components and 12% of sugar in this component. How many percents of sugar is represented in the whole tea?
- Budget plan
In the construction of the building, the planned budget exceeded 13%, which was 32,500 euros. How many euros cost built the building?
- Special watch
Fero bought a special watch on the market. They have only one (minute) hand and a display that shows which angle between the hour and minute hand. How many hours it was when his watch showed - the minute hand points to number 2; the display shows 125°?
- Barrel with water
The water barrel has a weight of 52 kg. When we pour a quarter of the water, the weight of the barrel is reduced to 40 kg. Determine the weight of the empty barrel.
- Air thermal
Imagine that a unit of air rises at 3000 meters high, if temperature decreases 6 degrees celcius for every 1000 meter, what will be its temperature at 1400 meters, 2000 meters, 2500 meters and when it reaches the 3000 meter elevation. Starting temperature.
Seven bricklayers will build the house in 630 days. How many bricklayers do we need to take after 150 days to complete the building for (additional) 336 days?
- Equations - simple
Solve system of linear equations: x-2y=6 3x+2y=4
- Slant height
The slant height of cone is 5cm and the radius of its base is 3cm, find the volume of the cone
- Eq with reciprocal
Solve given equation with reciprocal member: a-6/a+10=4/8
- Nineteenth member
Find the nineteenth member of the arithmetic sequence: a1=33 d=5 find a19
- Minimum surface
Find the length, breadth, and height of the cuboid shaped box with a minimum surface area, into which 50 cuboid shaped blocks, each with length, breadth and height equal to 4 cm, 3 cm and 2 cm respectively can be packed.
- Apples 14
Maya bought 18 apples. She used 50% of the apples to make apple pies and 1/3 of the apples was mixed with other fruits to make salad. How many apples were left?
- 3d printer
3D printing ABS filament with diameter 1.75 mm has density 1.04 g/cm3. Find the length of m = 5 kg spool filament. (how to calculate length)
- Distance of lines
Find the distance of lines AE, CG in cuboid ABCDEFGH, if given | AB | = 3cm, | AD | = 2 cm, | AE | = 4cm
- Diofant equation
250x + 120y = 5640
- Deviation of the lines
Find the deviation of the lines AG, BH in the ABCDEFGH box-cuboid, if given | AB | = 3cm, | AD | = 2cm, | AE | = 4cm
- Pyramid cut
We cut the regular square pyramid with a parallel plane to the two parts (see figure). The volume of the smaller pyramid is 20% of the volume of the original one. The bottom of the base of the smaller pyramid has a content of 10 cm2. Find the area of the o