Examples for 8th grade - page 24
The areas of the two circles are in the ratio 1:15. The larger circle has diameter 25. Calculate the radius of the smaller circle.
- Fixed expenses 2013
Since 2013, the Slovak government plans to tax more small one person businesses. Instead of fixed expences 40% will be fixed expences 40% of gross income up to 420 Eur. Calculate what percentage of fixed expences will in 2013 pays from gross income 1093 E
- Cone in cylinder
The cylinder is inscribed cone. Determine the ratio of the volume of cone and cylinder. The ratio express as a decimal number and as percentage.
- Circle in rhombus
In the rhombus is inscribed circle. Contact points of touch divide the sides to parts of length 18 cm and 17 cm. Calculate the circle area.
- Runner 2
Marian run 12 meters in 8 seconds. How far would Marian run for 70 seconds, if still run at the same pace?
- Two tributaries
Two tributaries of the pool fill it in 10 hours. One of the tributaries would fill 15 hours. How long would fill the first tributary?
- Ski tow
The ski club has 168 pupils and used lift with 60 seats, while students always follow the same sequence in filling seats. How many times while riding a ski lift skier sitting in the same seat as the first run?
- Rope slack
Between two streets 20 m away give the lamp, which is in the middle and hanging 60 cm bellow the taut rope. Can be done with 20.5 meters rope?
- Two workers
The first worker completed the task by himself in 9 hours, the second in 18 hours. After two hours of joint work left first worker to a doctor and the second finished the job himself. How many hours worked second worker himself?
Head of logistics department informed the meeting of management of the same item is currently not available in sufficient quantity in all three warehouses of the company. We have the total 135 pieces. It was 37 pieces more in the warehouse No. 3 than in th
61% of pupils at the school to eat in the canteen, 1/61 of students who eat in the canteen eat lunch soup. a) What percentage of pupils who eat in the canteen and eat soup for lunch? b) What percentage of all pupils of school eat lunch soup?
Calculate the square root of these numbers:
- Regular 5-gon
Calculate area of the regular pentagon with side 11 cm.
- Four pupils
Four pupils divided $ 1938 so that the second received 20% less than the first, the third 1/6 less than a fourth and fourth $ 132 less than the first. How much money had each of them?
Cyclist started at 5:00 from point N to point O. After 20 minutes, followed him at the same speed the second cyclist. Walker, which went from O to N, started at 5:40. After 56 minutes he met the first cyclist and after next 16 minutes the second cyclist. D
- Electronics: Resistors in parallel
From relation for calculating the resistance of parallel combination of resistors: ? Calculate the R, if R1 = 8kΩ a R2 = 18kΩ
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.
Coffee merchant has coffee robusta and arabica species. 1 kg Robusta worth 450 CZK, Arabica 1 kg is 300 CZK more expensive. Calculate how many kilograms of Robusta and Arabica will need to produce 30 kg of the mixture so that the mixture cost is 490 CZK p
Joshka had € 15. Mama took him 15%. How many had left?
The shepherd has fewer than 500 sheep; where they can be up to 2, 3, 4, 5, 6 row is always 1 remain, and as can be increased up to 7 rows of the sheep, and it is not increased no ovine. How many sheep has a shepherd?