Examples for 8th grade - page 19
The enrollment at a local college increased 3% over last year's enrollment of 7145. Find the increase in enrollment (x1) and the current enrollment (x2).
In stock are three kinds of branded coffee prices: I. kind......5.3 USD/kg II. kind......11.6 USD/kg III. kind.....5.8 USD/kg Mixing these three species in the ratio 2:8:3 create a mixture. What will be the price of 800 grams of this mixture?
In rectangle ABCD with sides |AB|=11, |AD|=12 is from point A guided perpendicular to the diagonal BD, which intersects at point P. Determine the ratio ?.
Find all divisors of number 418. How many are them?
- Water inlets
Inlet valve with a flow rate of 12 liters per second is filled tank for 72 minutes. How long take to fill full tank if we open one more such valve half an hour after?
- Tea blend
Tea blends are maked from two kinds of tea. In standard tea mixture are two teas in the ratio 1:3 and 40 g costs 42 CZK. In the premium tea mixture are weighing two teas in the ratio 1:1 and 50 grams costs 60 CZK. How much cost 10 grams of more expensive k
The area of trapezium is 35cm2 find its altitude if the bases are 6cm and 8cm.
Cuboid ABCDEFGH with 10 cm height has a base edge length 6 cm and 8 cm. Determine angle between body diagonal and the base plane (round to degrees).
- The percentages in practice
If every tenth apple on the tree is rotten it can be expressed by percentages: 10% of the apples on the tree is rotten. Tell percent using the following information: a. in June rained 6 days b, increase worker pay 500 euros to 50 euros c, grabbed 21 fro
Wha is the distance between the origin and the point (23; -7)?
- Water tank
Water tank shape cuboid has a width of 3.3 m and length twice larger. How high will reach water if water flow into 15 liters of water per second during 23 minutes?
Swimming pool is long 110 m and 30 m wide. The plan of the city is shown as a rectangle with area 13200 cm2. What scale is the city plan?
- Two rooms
Woman cleans the room in 30 minutes a man in 90 minutes. How long will take they clean two rooms?
- Cube and water
How many liters of water can fit into a cube with an edge length of 0.11 m?
- Triangular prism
Calculate the surface area and volume of a triangular prism, base right triangle if a = 3 cm, b = 4 cm, c = 5 cm and height of prism h=12 cm.
For the first week of February by influenza 5% of children in kindergarten. The second week ill 9 next children, bringing the number of patients increased to 20%. How many children went to the kindergarten?
- The camp
At the end of the camp a 9 friends exchanged addresses. Any friend gave remaining 8 friends his card. How many addresses they exchanged?
To the market is introducing a new product, the first week is sold at a reduced price. 5 products is sell at an entry price same as 3 products at the normal price. How much % is reduced price less than the current price for this product?
- Hexagon A
Calculate area of regular hexagon inscribed in circle with radius r=7 m.
The cylinder surface is 139 dm2, its height is equal to the radius of the base. Calculate height of this cylinder.