Examples for 8th grade - page 56
- Working together on project
Two employees working on the project. First make it alone for 20 days the second for 24 days. How many days will take to complete project if 5 days they work together then first will take two days holiday and after returning they completes a project toget
If the current way to school was 2 km shorter then if Milan swipe one half he will have already one quarter of the way to school behind. How long is Milan's way to school?
- Diagonals of a rhombus
One of the diagonals of a rhombus is twice as the other. If the sum of the lengths of the diagonals is 24, find the area of the rhombus.
The message is spreading that each day has doubled the number of people who know about it. All know message for 20 days. How long known it eighth people?
- One percent
One percent of all the lights in the city are LED, the remaining 99% are conventional. Other types are not there. John counted them honestly but he had counted only conventional. After a good dinner he registered numbers and he have notice that from all t
Calculate the length of the hypotenuse of a right triangle if the length of one leg is 4 cm and its content area is 16 square centimeters.
- Baskets of apples
Grandfather gathered apples into baskets. He filled one large and three small baskets. Small baskets are identical and each can hold 3 kg of apples less than in a large basket. In small baskets together 3 kg of apples over a large basket. How many kilogram
On two trees sitting 17 ravens. If 3 ravens flew from first to second tree and 5 ravens took off from second tree then the first tree has 2 times more ravens than second tree. How many ravens was originally on every tree?
- Average speed
What is the average speed you have to move the way around the world in 80 days? (Path along the equator, round to km/h).
- Sales off
shoes cost x euros. First they are discounted by 50%, and then 25% of the new amount. Determine what percentage of the total cost is cheaper.
Daniel, Jolana and Stano collected together 34 blackberries. Daniel collected 8 blackberries more than Jolana, Jolana 4 more than Stano. Determine the number blackberries each collected .
- Jane class
When asked how many students are in class, Jane said, if we increase the number of students in our class by hundred % and then add half the number of students, we get 100. How many students are in Jane's class?
- Water wessel
The vessel containing water has a weight 19 kg. After pouring half the water its weigth 11 kg. What is the weight of the empty vessel?
- Price increase 2x
If two consecutive times we increase the price of the product by 20%, how many % is higher final price than the original?
- Copper wire
What is the weight of 1000 m copper wire with a diameter of 5 mm when rezistivity p = 8.8 g / cm3?
- Cuboid and ratio
Cuboid has dimensions in ratio 1:2:6 and the surface area of the cuboid is 1000 dm2. Calculate the volume of the cuboid.
Calculate the surface area and volume of a prism with a body height h = 10 cm and its base has shape of a rhomboid with sides a = 5.8 cm, b = 3 cm and the distance of its two longer sides is w = 2.4 cm.
Car goes some distance in 3 hours and 20 minutes. If it increase speed by 10 km/h, i goes this distance in 2.5 hours. Calculate the distance.
- Hexagon = 8 parts
Divide the regular hexagon into eight equal parts.
Paul save 155Kč in 46 2 Kc and 5Kc coins. How much saved 2Kc and 5Kc coins?