Examples for 8th grade - page 37
Peter demolish box hole in the wall for window frame 48×48 cm. When they came masters fitted frame and window will be found that glass is 13.7 cm from the hole in each direction. Calculate how much percent less light enters the window than hole?
Peter broke the window glass with size 110 cm and 90 cm. 1 square meter of glass costs 8 Euro. How much money is need to pay for a new glass?
A team of colleagues done the work in 20 days. After adding 2 colleagues from the beginning the work was completed in 15 days. How many members has the colleague team?
Coffee from the machine in the cup cost 25 cents. Coffee is 20 cents more expensive than the cup. How much is the cup?
Rectangle ABCD has dimensions of 9 cm and 6 cm. Rectangle PQRS has dimensions 7 cm and 8 cm. Determine coefficient of the similarity k of the rectangles, if they aren't similar enter zero as the coefficient of similarity.
- Cylinder - h2
Cylinder volume is 2.7 liters. Base area is 1 dm2. Calculate the height of the cylinder.
- Hiker and cyclist
At 7 PM hiker started at 6 km/h to hike. After 3 hrs. later started on the same trip cyclist at speed of 15 km/h. After an hour of driving a flat tire and take him half hours to correct defect. At what time catch up cyclist with hiker?
Wha is the distance between the origin and the point (23; -7)?
How many liters of water per second can go via trough, which has a cross section of semicircle with radius 2.5 m and speed of water is 74 cm per second?
Mirka spent on a trip for gifts half pocket. For the third remain money bought a bagel. Six euros left her. How many euros had Mirka in pocket?
Flowerbed has the shape of an isosceles obtuse triangle. Arm has a size 6.1 meters and an angle opposite to the base size is 93°. What is the distance from the base to opposite vertex?
- BW-BS balls
Adam has a full box of balls that are large or small, black or white. Ratio of large and small balls is 5:3. Within the large balls the ratio of the black to white is 1:2 and between small balls the ratio of the black to white is 1:8 What is the ratio of.
- Square and circle
Into square is inscribed circle with diameter 10 cm.What is difference between circumference square and circle?
What distance will describe the tip of minute hand 6 cm long for 20 minutes when we know the starting position with finally enclose hands each other 120°?
Mr. Johnson's had monthly salary 966 USD since the beginning of year. From which month his salary was increased by 74 USD, when in year earned 11814 USD (enter as a number from 1 to 12)?
For horizontal distance 3 km road rise by 5.4 m. Calculate the road pitch in ‰ (permille, parts per thousand).
- Rhombus IV
Calculate the length of the diagonals of the rhombus, whose lengths are in the ratio 1: 2 and a rhombus side is 35 cm.
Two fifth-graders teams competing in math competitions - in Mathematical Olympiad and Pytagoriade. Of the 33 students competed in at least one of the contest 22 students. Students who competed only in Pytagoriade was twice more than those who just competed
Calculate the height of 3 liter pot with shape cylinder with a diameter of 10 cm.
Jarek bought new trousers, but the trousers were too long. Their length was in the ratio 5: 8 to Jarek height. Mother his trousers cut by 4 cm, thus the original ratio decreased by 4%. Determine Jarek's high.