Examples for 8th grade - page 84
- Boys and girls 2
The ratio of boys to girls in math club is 4:3 . After 8 more girls joined the Club, the ratio become 1:1. How many members are there in the club now?
- Probably member
Look at the series 2,6,25,96,285, ? What number should come next?
- Odd numbers
The sum of four consecutive odd numbers is 1048. Find those numbers ...
- Content area and percents
Determine what percentage is smaller cube surface, when the surface area of the wall decreases by 25%.
8 girls wants to play volleyball against boys. On the field at one time can be six players per team. How many initial teams of this girls may trainer to choose?
- Football season
Dalibor and Adam together scored 97 goals in the season. Adam scored 9 goals more than Dalibor. How many goals scored each?
- Two aircraft
Two planes fly to the airport. At some point, the first airplane is away from the airport 98 km and the second 138 km. The first aircraft flies at an average speed of 420 km/h, the second average speed is 360 km/h, while the tracks of both planes are perpe
The annual average rainfall in India was in Cherrapunji in the year 1981 26 461 mm. How many hectoliters of water fell on 1 m2? Would fit this amount of water into a cube of three meters?
200 boxes have been straightened in three rows. The first was 13 more than in the second, and in the second was one fifth more than in the third one. How many boxes are in each row?
- Map scale
On a 1:1000 scale map is a rectangular land of 4.2 cm and 5.8 cm. What is the area of this land in square meters?
- The cylinder base
The cylinder with a base of 8 dm2 has a volume of 120 liters. From a cylinder fully filled with water, 40 liters of water was removed. At what height from the bottom /with precision to dm/ is the water level?
9 workers dig a canal 120 meters long for eight hours. For how long would be dig five workers canal 200 meters long?
- Syringe and patient
In 1 ampoule of 2 ml is 15 mg of Dipidol. The patient should receive 10 mg. How much ml do I draw into the syringe?
- 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?
- Tree trunk
From the tree trunk, the diameter at the narrower end is 28 cm, a beam of square cross-section is to be made. Calculate the longest side of the largest possible square cross-section.
- Washing mashine
Family buy a washing machine for 350e. Cash paid 280e. What percentage of the total price must still pay the washer?
- Diagonals in diamons/rhombus
Rhombus ABCD has side length AB = 4 cm and a length of one diagonal of 6.4 cm. Calculate the length of the other diagonal.
- Acid solution
By adding 250 grams of a 96% solution of sulfuric acid to its 3% solution its initial concentration was changed to 25%. How many grams of 3% of the acid were used for dilution?
- Two sisters
Two sisters together have 54 CDs. 6/8 CDs has younger sister and is equal to 3/5 of CDs older sisters. How many CDs has each of the sisters?
- Cube surface area
The surface of the cube was originally 216 centimeters square. The surface of the cube has shrunk from 216 to 54 centimeters sq. Calculate how much percent the edge of the cube has decreased.