Examples for 8th grade - page 24
- Price reduction
Price of camera is 800 USD on sale its price reduced to 423 USD. Calculate the percentage reduction in the price of the camera.
Five pumps pumped 1,800 hl of water for 3 hours. How many hectoliters of water pump same two powerful pumps for six hours?
- Pumps A and B
Pump A fill the tank for 12 minutes, pump B for 24 minutes. How long will take to fill the tank if he is only three minutes works A and then both pumps A and B?
Large backpack cost CZK 1352, little is 35% cheaper. How much we paid for 5 large and 2 small backpacks?
- Bundle of candies
In the store has 168 chocolates, caramel candies 224 and 196 hard candies. How many packages we can do and how many of candies will be in each package?
- Distance runner
Distance runner already climbed three fifths of the total route. Thus passed 90 km. How many km he have to stop? How long is his route?
- Water level
How high reaches the water in the cylindrical barell with a diameter of 12 cm if there is a liter of water? Express in cm with an accuracy of 1 decimal place.
How many different ways can initiate a game of chess (first pass)?
- Cuboid aquarium
Cuboid 25 times 30 cm. How long is third side if cuboid contains 30 liters of water?
One half of rope use Mam for packaging, half of the rest got son, half of the rest he took father and two fifths of what remained, got daughter. Remained 52 cm of rope. How long was rope at the beginning?
In the front row sitting three students and in every other row 11 students more than the previous row. Determine how many students are in the room when the room is 9 lines, and determine how many students are in the seventh row.
- Average height
In a class are 34 students. The average height of students is 165 cm. What will be the average height of students in the classroom when two pupils tall 176 cm and 170 cm moved from this school/class?
Margaret and Zdena weighs the same and Petra 3 kg more. Together weigh 156 kg. How much does they weigh?
- Classs mean
Class size is 30 students, math was not worse than sign 2. Determine the number of pupils who were sign 1 if the class had a 1.4 sign average.
- Sales off
Goods is worth € 31 and the price of goods fell two weeks in a row by 10%. How many % decreased overall?
- Ski class
Class attend 30 boys and some number of girls. Ski training was attended by 28 boys and all the girls, which was 95% of all students. How many girls attend this class? How many percent is that?
A one-third of unknown number is equal to five times as great as the difference of the same unknown number and number 28. Determine the unknown number.
- 7 roses
Peter buys 7 roses. When he pay for it left him 4 euro. If he bought 5 roses left him 40 euros. How many euros had Peter before buying?
Less than 20 children is played various games on the yard. They can create a pairs, triso and quartets. How many children were in the yard when Annie came to them?
- Do you solve this?
Determine area S of rectangle and length of its sides if its perimeter is 96 cm.