Examples for 9th grade - page 27
In the bath is 30 liters of hot water. Then added 38 liters of cold water at temperature of 17 °C decreased temperature of water to 48 °C. What was the initial temperature of the hot water?
Subway train went between two stations that gradually accelerated for 20 seconds and reached a speed of 80 km/h. At this rate, went 41 seconds. Then 17 seconds slowed to a stop. What was the distance between the stations?
How many grams of 65% and 50% acid is to be mixed to give 240 g acid with a concentration of 60%?
- Four classses
Students of all 7, 8 and 9 classes in one school may take up 4,5,6 and 7 abreast and nobody will left. How many is the average count of pupils in one class if there are always four classes each grade?
- Roof tiles
The roof has a trapezoidal shape with bases of 15 m and 10 m, height of roof is 4 meters. How many tiles will need if on 1 m2 should be used 8 tiles?
- Cars motion
From point A car start at the speed of 90 km/h. Against it departs from the point B at the same time another car at 60 km/h. For how long and where they met if the distance between A and B is 180 km?
- Three friends
Divide 570 euros to three friends so that first will get 50 euros less than the second and third twice more than the first. How many euros will get everyone?
- The book
If one day you read p pages, you will read the book 24 days. If you read each day 10 pages more, you would read a book in 16 days. How many pages have the book?
Enterprise sold 7/12 of their products to foreign markets and 2/5 of the remainder sold at home. How many % of the products is still in stock?
Albert, Beny, Cyril and Dan worked on summerjob. From the total revenue Albert received 2/5, Beny 1/6 , 3/10 Cyril and Dan the rest which is 324 euros. How many euros earned every one of them?
The first alloy is a mixture of two metals in the ratio 1:2, the second is a mixture of same metals in the ratio 2:3. At what ratio we have these two alloys put into the furnace to obtain a new metal alloy with ratio 17:27? (All three ratios correspond to.
- Isosceles III
The base of the isosceles triangle is 24 cm area 416 cm2. Calculate the perimeter of this triangle.
Maple peak is visible from a distance 4 m from the trunk from a height of 1.7 m at angle 50°. Determine the height of the maple.
- Plastic pipe
Calculate weight of the plastic pipe with diameter d = 60 mm and length 400 cm if the wall thickness is 6 mm and the density of plastic is 1228 kg/m3.
Mr. Gherkin use for fertilization 9% solution of fertilizer. 7 liters of it still left. How much water must be added to the solution to make only 5% solution?
A passenger train traveled for 4 hours 136 km. 2.7 hours after its departure started fast train and caught it on 324 km. How many km/h is different its average speeds?
- Squaring the Circle
Calculating side of the square with the same area as the circle of radius 18.
In what quadrant is a 1501° angle?
Cuboid with edge a=14 cm and body diagonal u=42 cm has volume V=10976 cm3. Calculate the length of the other edges.
- Right triangle
Right triangle ABC with side a = 16 and the area S = 80. Calculate the length of the remaining sides.