Number of problems found: 726
If the fifth-grade class left 20% of students and in the seventh grade were added two pupils, in the eighth one pupil, the number has not changed in the ninth grade, but it is now tenth students less than it was in the fifth grade. How many pupils are in
- Solutions, mixtures
We have 2 liters of 20% solution available. How much 70% solution do we need to add to it to get a 30% solution?
In a 1-meter diameter cylinder is 1413 liters of water, which is 60% of the cylinder. Calculate the cylinder height in meters, do not write the units. The resulting value round and write as an integer.
- Fish population
The number of fish in a lake decreased by 10% during period of one year. Last year there were 500 fish in the lake. What is the fish population this year?
- Internet anywhere
In school, 60% of pupils have access to the internet at home. A group of 8 students is chosen at random. Find the probability that a) exactly 5 have access to the internet. b) At least 6 students have access to the internet
- Reduce of the volume
Calculate how many % reduce the volume of the cube is we reduced length of each edge by 10%.
The length of the rectangular hop garden Mr. Smith increased by 25% and its width by 30%. What is the percentage change in area of hop garden?
- The ball
The ball has a radius of 2m. What percentage of the surface and volume is another sphere whose radius is 20% larger?
Two members will make profit 52 000, - EUR. The forst earned 8% more and the second 10% more and thus earned together 56 700, - EUR. How many will initially each earn?
The company charges for office equipment louvers total 262 Eur. From the delivery bill is obvious that the louvers are 76 Eur expensive than their installation. What percentage of the total charged is the installation of louvers?
- Red balls
In the bag there are 3 red, 12 blue and 8 green balls. How many red balls we must be attached to the bag if we want the probability of pulling out the red balls was 20%?
- Prospering students
There are girls and 30 boys in the class. Boys prospering 28, girls all. How many girls are in the class and how many boys are there, if all the prospering students are 95%?
- Electricity consumption cost
Last year Karol family reduced its electricity consumption by 31% compared to the previous year and paid CZK 2883 less. How many CZK is electricity last year and how many two year ago?
- Water reservoir
The reservoir shape of a cylinder having a diameter 8 m and a height 2.8 m. The device indicates that the reservoir contains 800 hectoliters of water. Calculate how much % of volume is used.
Ladies sweater was twice discounted. First by 8%, then by 8% of the new price. Its final price was 66 €. Determine the original price of the sweater.
Skis, which cost € 800, became 25% more expensive before the season. After the season, they became cheaper again by 25%. How many euros did the skis cost after the discount?
- Percent change
If the length of a rectangle is increased by 25% and the width is decreased by 10%, the area of the rectangle is larger than the area of the original rectangle by what percent?
- Second hand store
The price of goods in the store for used goods is determined by agreement, while the sale price is deducted 15% commission - for the owner of the store. Matúš's parents decided to sell the TV so that their net profit was at least 50 euros. What was the mi
- The notebook
After rising by 40%, the notebook cost 10.50 euros. How much did this notebook cost if it increased in price by only 20% instead of 40%?
- Disinfecting solution
How much distilled water is necessary to pour into 500 ml of 33% hydrogen peroxide solution to obtain 3% disinfecting solution?
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