Examples for 8th grade - page 36
- Heron backlaw
Calculate missing side in a triangle with sides 33 and 27 and area 118.3.
- The cyclist
The cyclist went from village to town. First half of journey went at 19 km/h. The second half of the journey, which mostly fell, went at 33 km/h. All journey took 67 minutes. Calculate the distance from the village to the town.
- Dried apples
How many kilograms of fresh apples id needed to 120 kg of dried apples when from 0.4 tons of fresh apples we get 75 kg of dried apples?
Of the 80 people 50 people ill cancer. What percentage of people isn't ill?
How many tiles of 20 cm and 30 cm can build a square if we have a maximum 100 tiles?
Three siblings had saved up a total of 1,274 CZK. Peter had saved up to 15% more than Jirka and Hanka 10% less than Peter. How much money they saved each one of them?
Trader ordered from the manufacturer 200 cut glass. The manufacturer confirmed the order that the glass in boxes sent a kit containing either four or six glasses. Total sent 41 boxes. a) How many boxes will contain only 4 glasses? b) How many boxes will co
John, Teresa, Daniel and Paul have summary 56 years. Their ages are in a ratio of 1:2:5:6. Determine how many years have each of them.
- After 16 years
After 16 years will Dana be five times older as she was four years ago. After how many years will Dana celebrate her 16th birthday?
- Pedestrian and the cyclist
Pedestrian and cyclist went against each from the two cities that are distant 40 km. Pedestrian started 30 minutes before the cyclist and walk an average speed of 5 km/h. What speed went cyclist when met after 120 minutes from the start of the pedestrian?
- Two trains
Two trains go at each other. First at speed 40 km/h and the second at speed 60 km/h. At what distance will be 30 minutes before they will meet?
- Surface area 2
Calculate how many % reduce the surface area of the cube is we reduced length of each edge by 10%.
- Diagonal - simple
Calculate the length of the diagonal of a rectangle with dimensions 5 cm and 12 cm.
- Three friends
Peter is eight times older than Rado, Rado is 3 times younger than Joseph. Together they have 120 years. Determine how many are each of them.
Mom is 39 years old. Karl is eight years and Paul 4 years. For many years mother would old just like two children together?
- Cube and water
How many liters of water can fit into a cube with an edge length of 0.11 m?
- Aquarium 6
How high is the water level in the aquarium with a rectangular base 40cm and 50cm if it is filled 0,65hl of water?
- Travel by bus
Five girls traveling by bus. Each holds in each hand two baskets. Each basket contains 5 cats. Each cat has 5 kittens. 3 girls getting off the bus and another girl without baskets go on board. The bus control driver. How many legs are in the bus?
- Family parcels
In father will he divided the land so that the older son had three bigger part than younger son. Later elder son gave 2.5 ha field to younger and they had both the same. Determine the area of family parcel.
- The rod
The rod is painted in four colors. 55% of the bar is painted in blue, green 0.2 of rod, 1/8 is brown and the remaining 45 cm of white. How long is rod?