Examples for 8th grade - page 34

  1. Efficiency
    rychlovarna-kanvica What is the power output of kettle 2 kW with efficiency 90%?
  2. Rectangle
    rectangles_8 Perimeter of rectangle is 48 cm. Calculate its dimensions if they are in the ratio 5:3 (width:height)
  3. Pears
    hrusky Andrew, Lenka and Rasto have together 232 pears. Lenka has 28 more than Rasto and Rasto pears have 96 more than Andrew. Determine how much each of them has pears.
  4. Solution
    chemia What amount of 80% solution and what amount of water is needed to mix in order to obtain two liters of 60% solution of this mixture?
  5. Three siblings
    brothers Three siblings have birthday in one day-today. Together they have 35 years today. The youngest is three years younger than middle and the oldest is 5 years older than middle. How old is each?
  6. Brackets
    brackets Place one pair of brackets in expression 20-16 + 10 - 4 - 2 so that the result will be 0.
  7. Water lake
    jezirko The length of the lake water is 8 meters width 7 meters and depth 120 centimeters. How many liters of water can fit into the water lake?
  8. Sisters
    sestry20091 Sisters Janka and Danka are saved together 220 CZK. On a trip to Janka wants to take a fifth of her savings and Danka quarter. Then they will have 50 CZK on the trip. How much money saved Janka and Danka?
  9. Mukls
    Chinese women workers The working group, in which 6 workers would ordered job completed within 21 working days. How many workers must be accept yet that the contract will be completed in 14 working days?
  10. Plan scale
    geodet At what scale is drawn plan of the building, where one side of the building is 45 meters long is on the plan expressed by a straight line 12 mm long.
  11. Freight and passenger car
    1999_Daewoo_Leganza The truck starts at 8 pm at 30 km/h. Passenger car starts at 8 pm at 40 km/h. Passenger arrives in the destination city 1 hour and 45 min earlier. What is the distance between the city of departure and destination city?
  12. Unknown integer
    cross Find the smallest integer that: divided by 2, the remainder is 1 divided by 3 the remainder is 2, divided by 4 remainder is 3, ... divided by eight reminder is 7, by 9 reminder is 8.
  13. The professor's birthday
    prof_einstein Professor of mathematics had 36 birthdays. The director congratulated him. The professor asked the director: "And how old are you?" The director replied: "I'm exactly twice as many years than you were when I was old as to you today." How old is the direc
  14. Flowerbed
    flowers On the flowerbed was planted 310 flowers - pansies and crayons. During the first week wilts quarter of pansies and an eighth crayons, which is 20% of all flowers. How many pansies were planted on the flowerbed?
  15. Addends
    1plus1 Number 389 divide into the two addends that the first was 6 greater than 60% of the second. Determine these addends.
  16. Equilateral triangle
    3angle_in_circle How long should be the minimum radius of the circular plate to be cut equilateral triangle with side 7 mm from it?
  17. ŽSR
    luzianky Calculate fixed annual personnel costs of operating monorail line 106 km long if every 5 km is station, which serve three people - one dispatcher and two switchman in 3-shift operation. Consider the average salary of the employee 847 €.
  18. Weightlifter
    culturist Weightlifter lifted 75% of its weight. Determine how much weight lifted when he weighs 132 kg.
  19. Football match 4
    futball_ball In a football match with the Italy lost 3 goals with Germans. Totally fell 5 goals in the match. Determine the number of goals of Italy and Germany.
  20. Loading car
    voz The car was loaded with 78 boxes weighing 19 kg. How many 25kg boxes can load if the total weight is the same?

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