Examples for 8th grade - page 64

  1. Prism
    hranol_3bokovy_1 Find the volume and surface area of prism with base of an equilateral triangle with side 7 dm long and the body height of 1.5 m.
  2. Gearing
    prevod Gearing consists of two wheels, one is 88 and second 56 teeth. How many times turns smaller wheel to fit the same teeth as in the beginning? How many times will turn biggest wheel?
  3. 4 pipes
    roury The tank flows out by 4 pipes in 6 hours 120 hl water. How much water flows out of 5 pipes of the same diameter in 14 hours?
  4. Pyramid 4sides
    pyramid_2 Calculate the volume and the surface of a regular quadrangular pyramid when the edge of the base is 4 cm long and the height of the pyramid is 7 cm.
  5. Solutions
    bilde How much 60% solution and how much 35% solution is needed to create 100 l of 40% solution?
  6. Probability - tickets
    zreby What is the probability that when you have 25 tickets in 5000 that you wins the first (one) prize?
  7. Diagonal - simple
    makac Calculate the length of the diagonal of a rectangle with dimensions 5 cm and 12 cm.
  8. Sinus
    sine_cosine Determine the smallest integer p for which the equation 4 sin x = p has no solution.
  9. Chord 5
    kruhy It is given circle k / S; 5 cm /. Its chord MN is 3 cm away from the center of the circle . Calculate its length.
  10. Mrs XY
    crime Mrs Novak is employed. In January 2015 the gross income reached € 1348. Insurance is a 323.52 euros, and income taz 153.67 euros. Employer precipitated Mrs. Novak in recent clashes € 115, of which 57 euro for the savings account, and 58 euros for repayment
  11. Square garden
    garden_4 On the plan with a scale of 1:1500 is drawn as a square garden with area 81 cm2. How many meters is long garden fence? Determine the actual acreage gardens.
  12. Trip
    pomarancovy-dzus On the trip drank 3/10 of pupils tea, 2/5 cola, 1/4 mineral water and remaining 3 juice. How many students were on the trip?
  13. Cube 6
    water_cube Surface area of one wall cube is 1600 cm square. How many liters of water can fit into the cube?
  14. Coffee shop
    coffee-beans To the coffee shop brought 2 types of coffee totally 50 kg. The first type was CZK 220 per kilogram, coffee second type 300 CZK per 1 kg. For all the coffee trader earned CZK 12,000. How many kilograms of coffee of first type and how many kilograms of cof
  15. Borrowed book
    TB Jane must as soon as possible return a borrowed book. She figured that when she read 15 pages a day return book in time. Then she read 18 pages a day and then return the book one day before. How many pages should have a book?
  16. Sea water
    salt_5 One tonne of sea water contains 25 kg of salt. How many tonnes of sea water need to be evaporated to obtain 1 tonne of salt?
  17. Three days
    skolske-zosity_1 During the three days sold in stationery 1490 workbooks. The first day sold about workbooks more than third day. The second day 190 workbooks sold less than third day. How many workbooks sold during each day?
  18. Saving
    2kc Paul save 155Kč in 46 2 Kc and 5Kc coins. How much saved 2Kc and 5Kc coins?
  19. Car
    sanitka_1 Car goes some distance in 3 hours and 20 minutes. If it increase speed by 10 km/h, i goes this distance in 2.5 hours. Calculate the distance.
  20. Apprentice
    ucen Worker and apprentice execute the work for 6 hours. Worker performs himself in 10 hours. How long do the work of an apprentice?

Do you have interesting mathematical example that you can't solve it? Enter it and we can try to solve it.



To this e-mail address we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.