Latest word problems
Number of problems found: 722
- Water percent
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
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
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
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
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?
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
How long will it take to save € 9,000 by depositing € 200 at the beginning of each year at 2% interest?
- What is
What is the annual percentage increase in the city when the population has tripled in 20 years?
- Age of family
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
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
Calculate the value of the expression z/3 - 2 z/9 + 1/6, for z = 2
- AL wire
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
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 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
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
What is the length of the arc of a circle with a diameter of 46 cm, which belongs to a central angle of 30°?
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
What is the average speed of a cycle traveling at 20 km in 60 minutes in km/h?
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
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.