New math problems - page 8

  1. Tree shadow
    tree3 The shadow of the tree is 16 meters long. Shadow of two meters high tourist sign beside standing is 3.2 meters long. What height has tree (in meters)?
  2. Kangaroo
    klokan_1 Kangaroo do 10 jumps in 1 minute and then three minutes lie , then will make 10 jumps in 1 minute and 3 minutes lie, and so on. Find the shortest time in which kangaroo do 30 jumps.
  3. Two aces
    cards_7 From a 32 card box we randomly pick 1 card and then 2 more cards. What is the probability that last two drawn cards are aces?
  4. Sun rays
    sfinga-a-cheopsova-pyramida-w-4066 If the sun's rays are at an angle 60° then famous Great Pyramid of Egypt (which is now high 137.3 meters) has 79.3 m long shadow. Calculate current height of neighboring chefren pyramid whose shadow is measured at the same time 78.8 m and the current hei
  5. Trapezoid MO-5-Z8
    lichobeznik-stredni_pricka_2 Trapezoid KLMN has bases 12 and 4 cm long. The area of triangle KMN is 9 cm2. What is the area of the trapezoid KLMN?
  6. Percentages 5
    usd_1 $5.25 is 7 1/2% of what number?
  7. Railway wagon
    cargo The railway wagon holds 75 m3 load. Wagon can carry a maximum weight of 30 tonnes. What is the maximum density that may have material with which we could fill this whole wagon? b) what amount of peat (density 350 kg/m3) can carry 15 wagons?
  8. Quadratic inequation
    eq2_8 If 5x + x² > 100, then x is not
  9. Cube in sphere
    sphere4 The sphere is inscribed cube with edge 8 cm. Find the radius of the sphere.
  10. Electricity consumption cost
    Temelin4veze1 Last year Karol family reduced its electricity consumption by 31% compared to the previous year and paid CZK 2883 less. How many CZK is electricity last year and how many two year ago?
  11. Trapezoid 15
    trapezoid3 Area of trapezoid is 266. What value is x if bases b1 is 2x-3, b2 is 2x+1 and height h is x+4
  12. Steamer
    parnik_3 At 6 hours 40 minutes steamer sailed from the port at speed 12 km/h. At exactly 10 hours started sail motorboat at speed 42 km/h. When motorboat will catch steamer?
  13. Real estate
    house Residential house has three entrances numbered by odd numbers arithmetic progression. The sum of the two numbers on the corner entrances is 50. Calculate the highest of this three numbers.
  14. Isosceles right triangle
    IsoscelesRightTriangle Contents of an isosceles right triangle is 18 dm2. Calculate the length of its base.
  15. Diagonals
    stvorec_7 Draw a square ABCD whose diagonals have a length of 6 cm
  16. Cubes
    krychlicky Carol with cut bar 12 cm x 12 cm x 135 cm to the cubes. Find the sum of all the surfaces of the resulting cubes.
  17. Concrete pedestal
    krychle_10 The carpenters made wooden mold on a concrete pedestal in the shape of a cube with edge 2 meter long. What is the area in which the concrete touches wooden molds? (No lid or bottom)
  18. Salami
    salama How many ways can we choose 5 pcs of salami, if we have 6 types of salami for 10 pieces and one type for 4 pieces?
  19. Trees
    jablone Along the road were planted 250 trees of two types. Cherry for 60 CZK apiece and apple 50 CZK apiece. The entire plantation cost 12,800 CZK. How many was cherries and apples?
  20. MO Z6-6-1
    kruhy_1 Write integers greater than 1 to the blanks in the following figure, so that each darker box was product of the numbers in the neighboring lighter boxes. What number is in the middle box?

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