Examples for 8th grade - page 9

  1. Hiker
    hiker Hiker went half of trip the first day, the third of trip the second day and remaines 13 km. How long trip he planned?
  2. Salary
    500euro Clerk got to pay 1200 Euros in banknotes of 50 and 200 Eur. Total got 9 banknotes. How many was which?
  3. Arithmetic average
    ap The arithmetic mean of the five numbers is exactly 8. The sum of these four numbers is 30. What is the fifth number?
  4. Tanker
    oil-tanker An oil tanker can be emptied by the first pump in 4.4 hours. Second pump can empty an tanker in 7.8 hours. If the first pump started at 8:00 and second 1.4 hour later, at what time will the tanker be empty?
  5. Ratio
    ratio_2 Unfold number 4712 in the ratio 10:14:7.
  6. Server
    p_pro Calculate how many average minutes a year is the web server is unavailable, the availability is 99.99%.
  7. Water
    tanks Mix 61 l of water with temperature of 48 °C, 58 l warm of 57 °C and 47 l water of 39 °C. What is the temperature of the mixed water immediately after mixing?
  8. Square
    squares_4 If we increase one side of square by its one-half then square perimeter increase by 10 cm. What is the side of the square?
  9. Trapezoid MO-5-Z8
    lichobeznik_mo_z8 ABCD is a trapezoid that lime segment CE divided into a triangle and parallelogram as shown. Point F is the midpoint of CE, DF line passes through the center of the segment BE and the area of the triangle CDE is 3 cm2. Determine the area of the trapezoid A
  10. Road - permille
    18procent 5 km long road begins at an altitude 500 meters above sea level and ends at a altitude 521 ASL. How many permille road rises?
  11. No. of divisors
    triangle_div How many different divisors has number ??
  12. Pumps 3
    pump_water Two pumps of the same power fill the garden pool for 10 hours. How many of these pumps would have to use if we want to shorten the filling of the pool to four hours?
  13. Three digits number
    3digit From the numbers 1, 2, 3, 4, 5 create three-digit numbers that digits not repeat and number is divisible by 2. How many numbers are there?
  14. Bouquet
    flowers_1 Gardener tying bouquet of flowers for 8 and none was left. Then he found that he could tying bouquet of 6 flowers and also none was left. How many have gardener flowers (minimum and maximum) if they had between 50 and 100 flowers?
  15. Word problem
    hungary-flag 349 students were on holiday in Hungary. 153 bought pizza, chips 18 pupils, 31 pupils bought soda, butter 28 pupils, 12 pupils fruits, vegetables 24 students. How much pay for all the food, if every meal cost 3.5 euros?
  16. Two cars
    cars_racing Two cars started against each other at the same time to journey long 225 km. First car went 35 km/h and second 48 km/h. What distance will be between this cars 20 minutes before meet?
  17. Cube wall
    kocka Surface of first cube wall his 361 cm2. Second cube area is 30% of the surface of the first cube. Determine the length of the edge of the second cube (x).
  18. Certificate
    ucitel There is 28 students in a class. From mathematics was'nt worse mark than 2. Average mark in mathematics was 1.4643. How many students have mark 1 and how many mark 2?
  19. Brothers and sisters
    family Lenka has as many brothers as sisters. Her brothers have twice as many sisters as brothers. How many brothers and sisters are in the family?
  20. Cube
    kocka_rubik The cube weighs 18 kg. How weight is cube of the same material, if its dimensions are 3-times smaller?

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