Grade - examples - page 203

  1. Stamps 2
    stamp_9 Dennis spent 34.15 on stamps. The number of .56 is 10 less than four times of stamps bought for .41. How many of each stamp did he buy?
  2. Trees
    hrusky_7 In the orchard, 38 apple trees and 20 pear trees grew. How many trees there grow?
  3. Square metal sheet
    plech_2 Four squares of 300 mm side were cut out from a square sheet metal plate with a side of 0,7 m. Express the fraction and the percentage of waste from the square metal sheet.
  4. Trees in alley
    tree_6 There are four trees in the alley between which the distances are 35m, 15m and 95m. Trees must be laid in the spaces so that the distance is the same and the maximum. How many trees will they put in and what will be the distance between them?
  5. Cube cut
    rezy The cube ABCDA'B'C'D ' has an edge of 12cm. Calculate the area of diagonal cut B DD'B '.
  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. Tickets
    tombola_4 On Monday, 33 tickets were sold. Every next day, twice as many as the previous day. How many tickets were sold on Friday and how many totally from Monday to Friday?
  8. Tilapia
    tilapia_1 A fish vendor sells 5/7 kilos of tilapia for 73.50. If you will buy 2 1/7 kilos of tilapia, how much will it cost?
  9. Land
    12-13-5-triangle Rectangular triangular land has area 30 square meters and 12 meters long leg. How many meters of the fence do you need for fencing this land?
  10. Cube root
    30gon_1 Find cube root of 18
  11. Isosceles trapezoid
    lich_2 The old father decided to change the top plate of an isosceles-like trapezoid with the basic dimensions of 120 cm and 60 cm, and the shoulder is 50 centimeters long. How much does it pay for a new plate and a square meter worth 17 euros?
  12. Scientific notation
    scientific Approximately 7.5x105 gallons of water flow over a waterfall each second. There are 8.6x104 seconds in 1 day. Select the approximate number of gallons of water that flow over the waterfall in 1 day.
  13. Mixed numbers
    zlomky_10 Rewrite mixed numbers so the fractions have the same denominator: 5 1/5 - 2 2/3
  14. The larger
    59_number The larger of two numbers is nine more than four times the smaller number. The sum of the two numbers is fifty-nine. Find the two numbers.
  15. Water lilies
    lekno_2 Water lilies are growing on the pond and their number is doubled every day. The whole layer is covered in 12 days. How many days will it cover 8 layers?
  16. Microorganisms
    microorganisms The first generation of micro-organisms has a population of 13500 members. Each next generation is 11/10 times the previous one. Find out how many generations will reach at least three times members of the first generation.
  17. Mushrooms
    huby_5 Grandfather gathered fresh mushrooms. The fifth was wormwood, and it was thrown away, the other dried up. He obtained 720 grams of dried mushrooms. How many kilograms did the grandfather collect, and by drying the mushrooms they lost 75% of their weight?
  18. Two municipalities
    promile_4 The horizontal distance between municipalities is 39 km. Average sinking is 7 per mille. What is the difference in height between these municipalities?
  19. Bulb
    bulb _2 A 60 W bulb consumes 0.12 kWh of electricity. How long did she stand light without a break?
  20. Pamela
    penize_48 Lara Pamela spends her salary of 3000 for food, clothing, recreation and savings, which are in the ratio of 48:20:15:37, respectively. How much does he spend for savings?

Do you have an 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.