Latest problems - page 18

  1. Two trains
    vlak_8 From station A, the freight train traveled at a speed of 40 km/h in 9h. When he drove 15km, the fast train started from station A in the same direction at a speed of 70km/h. When will it the freight train catch up?
  2. Fishing boat
    rybnik_4 The fishing boat caught 14 fish in one day. How many fish will catch 4 fishing boats in 8 days?
  3. Boats
    ship_7 Three-quarters of boats are white, 1/7 are blue and 9 are red. How many boats do we have?
  4. Jose and Kaitlyn
    ball_f_4 Jose and Kaitlyn have a contest to see who can throw a baseball the farthest. Kaitlyn wins, with a throw of 200 ft. If Jose threw the ball 3/4 as far as Kaitlyn, how far did Jose throw the ball?
  5. Equivalent expressions
    pizza_10 A coach took his team out for pizza after their last game. There were 14 players, so they had to sit in smaller groups at different tables. Six players sat at one table and got 4 small pizzas to share equally. The other players sat at the different table a
  6. Standard deviation
    standard-dev_1 Find standard deviation for dataset (grouped data): Age (years) No. Of Persons 0-10 15 10-20 15 20-30 23 30-40 22 40-50 25 50-60 10 60-70 5 70-80 10
  7. Combinations 7
    combinatorics A multi-course meal has 3 choices. 3 appetizers, 4 main courses, and 3 desserts. How many different combinations to choose from?
  8. Symmetry by plane
    roviny Determine the coordinates of a image of point A (3, -4, -6) at a symmetry that is determined by the plane x-y-4z-13 = 0
  9. Non linear eqs
    q2_non_linear Solve the system of non-linear equations: 3x2-3x-y=-2 -6x2-x-y=-7
  10. The factory
    clocks_13 The factory z can complete an order in 12 days, factory p in 18 days. For how many days does an order completed when the first two days work only the factory z and then both factories?
  11. Water reservoir
    nadrz_17 One drain hole emptied the water from the tank for 20 hours, with the second drain for 30 hours. How long will the water drain from this tank if we open two drains simultaneously?
  12. Beds
    stan_3 At the summer camp, there are 41 chalets. Some rooms are 3-beds, some 4-beds. How many campers from 140 are living in 3-bed?
  13. Pimps
    pirohy There were 24 pimps in the plate. Maros ate 12, his little sister four times less. How many pimps remained in the plate?
  14. Selling price
    usd_11 Find the selling price. Cost to store: $50 Markup: 10%
  15. Odd/even number
    numbers2_49 Pick any number. If that number is even, divide it by 2. If it's odd, multiply it by 3 and add 1. Now repeat the process with your new number. If you keep going, you'll eventually end up at 1. Every time. Prove. ..
  16. What is one third
    decimals What is 1/3 as a decimal? Give your answer rounded to 2 decimal places.
  17. Honza
    calendar_6 Honza is 13 years old and Peter 21 years old. After how many years are their ages will be at ratio 7: 9?
  18. Rectangular trapezoid
    right-trapezium-figure The ABCD rectangular trapezoid with the AB and CD bases is divided by the diagonal AC into two equilateral rectangular triangles. The length of the diagonal AC is 62cm. Calculate trapezium area in cm square and calculate how many differs perimeters of the.
  19. Harvesters
    kombajn_10 The first harvester will harvest the grain from the field in 20 hours, the second, the more powerful in 10 hours. How long will take harvest this field by both harvesters, if the second harvester has to be set up first and this takes 2 hours? The first har
  20. Bucket
    watertank_4 The bucket half filled with water weighs 5.55 kg, the full bucket weighs 9.85 kg. How much does the bucket weigh?

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