Examples for 8th grade

Number of problems found: 2874

  • Current in the conductor
    ohms-law Calculate the current in the conductor (in mA) if it is connected to a 4.5 V voltage source and its resistance is 20 (ohm).
  • The bulb
    bulbs What is the resistance of a filament lamp when it is connected to a 9V battery and has a current of 120 mA?
  • Seasonal sale
    bicycle_gears The bike became cheaper on the seasonal sale by 22%, which is 88 euros. At what price is it sold now?
  • An airplane
    aircraft-02 An airplane flies 1440 km in 2 1/4 hours. What is its average speed in km per hour?
  • Two shops
    ski_1 In two different shops, the same skis had the same price. In the first, however, they first became more expensive by 20% and then cheaper by 5%. In the second, they were first cheaper by 5% and then more expensive by 30%, so after these adjustments in the
  • Tulips
    tulipany Of the 120 tulips in the garden, 45 are red, 66 are yellow, the rest are brindle. What percentage of tulips in the garden are brindle?
  • 14 years
    family Kája is 14 years old. Mom 44. How many years will mom be 4 times older?
  • Dance ensembles
    dancers 4 dance ensembles were dancing at the festival. None had less than 10 and more than 20 members. All dancers from some of the two ensembles were represented in each dance. First, 31 participants were on the stage, then 32, 34, 35, 37, and 38. How many danc
  • Square gardens
    zahrada_1 The gardening colony with dimensions of 180 m and 300 m is to be completely divided into equally large square areas with the largest possible area. Calculate how many such square areas can be obtained and determine the side length of the square.
  • Pagans
    rohliky Jano and Michael ate pagans. Jano ate three more than Michael. The product of their counts (numbers) is 180. How many pagans did each of them eat?
  • One dice
    dice Calculate the probability of a roll of one dice with the numbers 1, 2, 3, 4, 5, 6 on the walls. Write the results in a notebook in the shape of a fraction in the basic form: 2/3. a, The number 1 falls on the cube. b, The number 5 falls on the cube. c, An
  • Gardens
    garden The area of the square garden is 3/4 of the area of the triangular garden with sides of 80 m, 50 m, 50 m. How many meters of the fence do we need to fence a square garden?
  • Roads
    mapa There are 4 roads from city A to city B. There are 5 roads from city B to city C. How many different routes can we come from city A to city C via city B?
  • The staircase
    schody The staircase has a total height of 3.6 m and forms an angle of 26° with the horizontal. Calculate the length of the whole staircase.
  • Two-element combinations
    combinatorics Write all two-element combinations from elements a, b, c, d.
  • Nautical miles
    mapa How many nautical miles do they sail if the route is shown on a 1:25 000 scale map with a 7.4 cm long line?
  • Borrowing bicycle
    cukriky Jakub lent a bicycle to friends who wanted to ride it. For a three-hour bike ride, Jakub received 2 chocolates. Yup. If you wanted a bike for 2 hours, you had to give Jakub 12 candies. Peter gave Jakub 1 chocolate and 3 candies. How long can Peter ride Ja
  • Ladder
    rebrik How long is a ladder that touches on a wall 4 meters high and its lower part is 3 meters away from the wall?
  • Ascend vs. descent
    lines Which function is growing? a) y = 2-x b) y = 20 c) y = (x + 2). (-5) d) y = x-2
  • Two xeroxes
    xerox The performances of the two copiers are in the ratio 3: 4. A machine with higher power will make 7,200 copies in one hour. How many copies will both machines make together in 5 hours?

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