Examples for 9th grade - page 30

  1. Diamond
    cerveny_kosoctverec Side length of diamond is 35 cm and the length of the diagonal is 56 cm. Calculate the height and length of the second diagonal.
  2. Painters
    painter First painter painted fence himself for 9 hours, the second painter 1.6 hours sooner than first, and the third painters slowest up to 20 hours. How long took them paint fence if worked together?
  3. Grandfather
    family_16 The grandfather is three years older than an grandmother. The average age of the grandmother, the grandfather and their seven grandchildren is 28 years. The grandchildren have a total of 105 years. Calculate how old is grandfather.
  4. Spirit
    lieh From 55% and 80% spirit we would like to produce 0.2 kg of 60% spirit. How many of them we must use in a solution?
  5. Cone container
    kuzel_1 Rotary cone-shaped container has a volume 1000 cubic cm and a height 12 cm. Calculate how much metal we need for making this package.
  6. Diagonal
    rectangles2 Diagonal of the rectangle has length 46.4 cm. Angle between diagonal and londer sife of rectangle is 22°. Calculate area of the rectangle.
  7. Password
    codes The voltage station is every day changing the master password, which consists of three letters. Code generation process does not change and is based on the following procedure: The following letters (A) to (I) correspond to different numbers from 1 to 9. I
  8. Enterprise and wages
    workers_3 The enterprise operates a total 162 workers and their average salary is M dollars. If the company has hire an additional 18 employees whose average wage would be the S dollars, would reduce the overall average salary in the company of 3.6%. Calculate the
  9. Bronze, tin and copper
    zvon Bronze is an alloy of tin and copper. An alloy of 10% tin and 90% copper is Gunmetal. If it contains 20% tin and 80% copper, it is bell metal. How many tons of molten bell metal and how many tons of copper is needed to make 100 tons of Gunmetal?
  10. Examination
    examination The class is 21 students. How many ways can choose two to examination?
  11. Rectangle - parallelogram
    nieco It is given a rectangle that is circumscribed by a circle with a radius of 5 cm. The short side of the rectangle measures 6 cm. Calculate the perimeter of a parallelogram ABCD whose vertices are the midpoints of the sides of the rectangle.
  12. ISO trapezoid v2
    lichobeznik bases of Isosceles trapezoid measured 12 cm and 5 cm and its perimeter is 21 cm. What is the are of a trapezoid?
  13. Summerjob
    pat_mat Albert, Beny, Cyril and Dan worked on summerjob. From the total revenue Albert received 2/5, Beny 1/6 , 3/10 Cyril and Dan the rest which is 324 euros. How many euros earned every one of them?
  14. Chalet
    turancar_autobus The children were on a school trip to the mountain . One third of the journey went by the train and continue by bus. When you get off the bus, they remained a third of the distance they traveled by bus. What part of journey children went by the bus (wrote
  15. Two workers
    workers_2 Two workers carry will do certain work for 12 days. After 8 days of working was one removed, and then the other finished the job alone in 10 days. For how many days would do this work alone each worker?
  16. Sales off
    sweater If a sweater sells for $ 19 after a 5% markdown, what was its original price?
  17. Invitations
    envelope For every 5 minutes writes Dana 10 invitations, while Anna 14 invitations. How long will write together 120 invitations?
  18. Train from Brno
    train_cd First train started from Brno at 8 am at 60 km per hour. Second train started from Opava at 7 o'clock at the speed of 40 kilometers per hour. In how many hours and how far from cities trains meet when the distance of cities is 200 kilometers.
  19. Vectors
    vectors Vector a has coordinates (8; 10) and vector b has coordinates (0; 17). If the vector c = b - a, what is the magnitude of the vector c?
  20. Plot
    rectangle_5 The length of the rectangle is 8 smaller than three times the width. If we increase the width by 5% of the length and the length is reduced by 14% of the width, the circumference of rectangle will be increased by 30 m. What are the dimensions of the rectan

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