Expression of a variable from the formula + percentages - math problems

Number of problems found: 84

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%?
Three groups
In the company, employees are divided into three groups. In the first group, which includes 12% of the company's total number of employees, the average salary is CZK 40,000, in the second group CZK 35,000, in the third group CZK 25,000. The average salary
Decibel
By what percentage does the sound intensity increase if the sound intensity level increases by 1 dB?
Bike cost
The father gave his son € 100 to buy a bicycle, which was 40% of the total amount of the bicycle. How much did the bike cost?
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?
Percentage increase
What is the annual percentage increase in the city when the population has tripled in 20 years?
The number 72
The number 72 increase by 25%. By how much % will you have to reduce the number you created to get the number 72 again?
Double price reduction
The price of TV has been reduced twice. First by 15% and later by another 10% of the reduced price. After this double price reduction, the TV was sold for 8,874 crowns. What was the original price of the TV?
Savings
The depositor regularly wants to invest the same amount of money in the financial institution at the beginning of the year and wants to save 10,000 euros at the end of the tenth year. What amount should he deposit if the annual interest rate for the annua
Triangular prism
The base of the perpendicular triangular prism is a rectangular triangle with a hypotenuse of 10 cm and one leg of 8 cm. The prism height is 75% of the perimeter of the base. Calculate the volume and surface of the prism.
Volume of wood
Every year, at the same time, an increase in the volume of wood in the forest is measured. The increase is regularly p% compared to the previous year. If in 10 years the volume of wood has increased by 10%, what is the number p?
Growth of wood
The annual growth of wood in the forest is estimated at 2%. In how many years will make the forest volume double?
The ball
The ball has a radius of 2m. What percentage of the surface and volume is another sphere whose radius is 20% larger?
Together m+w
Women 30%. Men are 360 more. How many are together?
Washing powder
A 10-kilogram pack of washing powder is M euros more expensive than a 5-kilogram pack of the same powder. A 5-kilogram package costs P euros. Five kilos of packaging is not worth it, because it is more expensive than half the price of 10 kilos. How much i
Square side
If we enlarge the square side a = 5m, its area will increase by 10,25%. How many percent will the side of the square increase? How many percent will it increase the circumference of the square?
Before yesterday
He merchant adds a sale sign in his shop window to the showed pair of shoes in the morning: "Today by p% cheaper than yesterday. " After a while, however, he decided that the sign saying: "Today 62.5% cheaper than the day before yesterday". Determine the
Folding table
The folding kitchen table has a rectangular shape with an area of 168dm² (side and is 14 dm long). If necessary, it can be enlarged by sliding two semi-circular plates (at sides b). How much percent will the table area increase? The result round to one-hu
Former price
The price of an article is cut by 10%, to restore it to the former value, by what percent the new price must be increased?
The observatory
The dome of the hemisphere-shaped observatory is 5.4 meters high. How many square meters of sheet metal needs to be covered to cover it, and 15 percent must be added to the minimum amount due to joints and waste?