Latest word problems

Number of problems found: 722

  • Water percent
    huby A 15 g sample of the substance contains 70% water. After drying, the weight was reduced to 9 g. What percentage of water is now in the sample?
  • Work together
    time Two bricklayers plastering a wall. The first would plaster it in 8 hours, the second in 12 hours. How many hours will they be done with the work if they work together?
  • Birthday paradox
    holland How large must the group of people be so that the probability that two people have a birthday on the same day of the year is greater than 90%?
  • The tent
    stan Calculate how much cover (without a floor) is used to make a tent that has the shape of a regular square pyramid. The edge of the base is 3 m long and the height of the tent is 2 m.
  • The water tank
    hydroglobus The water tank has the shape of a sphere with a radius of 2 m. How many liters of water will fit in the tank? How many kilograms of paint do we need to paint the tank, if we paint with 1 kg of paint 10 m2?
  • Lifespan
    normal_d The lifetime of a light bulb is a random variable with a normal distribution of x = 300 hours, σ = 35 hours. a) What is the probability that a randomly selected light bulb will have a lifespan of more than 320 hours? b) Up to what value of L hours can the
  • Slow saving in banks
    penize_5 How long will it take to save € 9,000 by depositing € 200 at the beginning of each year at 2% interest?
  • What is
    exp_growth2 What is the annual percentage increase in the city when the population has tripled in 20 years?
  • Age of family
    age The age of father and son is in the ratio 10: 3. The age of the father and daughter is in ratio 5: 2. How old are a father and a son if the daughter is 20?
  • Magnified cube
    cube_in_sphere If the lengths of the edges of the cube are extended by 5 cm, its volume will increase by 485 cm3. Determine the surface of both the original and the magnified cube.
  • Evaluate expression
    numbers Calculate the value of the expression z/3 - 2 z/9 + 1/6, for z = 2
  • AL wire
    vaha2 What is the weight of an aluminum wire 250 m long with a diameter of 2 mm, if the density of aluminum is p = 2700 kg/m cubic. Determine to the nearest gram.
  • Trapezoidal prism
    lich_hranol Calculate the volume of a prism with a trapezoidal base with side a = 6dm, side c = 4 dm, height of the prism = 8dm. The height of the trapezoid is va = 3dm.
  • Brass
    brass Brass is an alloy of copper and zinc in a ratio of 3: 2. How many grams does a component that required 270 g of copper weigh?
  • Runcated pyramid teapot
    komoly_jehlan The 35 cm high teapot has the shape of a truncated pyramid with the length of the edge of the lower square base a=50 cm and with the edges of the rectangular base b: 20 cm and c: 30 cm. How many liters of water will fit in the teapot?
  • Central angle
    obluk What is the length of the arc of a circle with a diameter of 46 cm, which belongs to a central angle of 30°?
  • Drivers
    clocks2 Driver Franta and driver Karel are friends. They leave the start-stop both at the same time in the afternoon - at 13.30. When will they meet again if Franta goes around his route in 50 minutes and Karel in 40 minutes?
  • Cyclist 12
    cyclist What is the average speed of a cycle traveling at 20 km in 60 minutes in km/h?
  • Ditch
    vykop The excavator dug 40% of the excavation in 2 hours 20 minutes. How long does it take him to dig the whole ditch?
  • Hectoliters of water
    valec2 There are 942 hectoliters of water in a cylindrical tank with an inner diameter of 6 m. The water reaches two thirds of the depth of the tank. Calculate its depth.

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