# Expression of a variable from the formula + percentages - practice problems

#### Number of problems found: 88

- Bronze

Bronze has 80% copper and 20% tin. How much copper will we need to produce bronze if we have 39kg of tin? - Discount

If someone gives u discount on "X" at 5% for 60 days. Then the discounted amount is 80000. find the actual amount? Discounted Amount=80000 rate=5% Period=60 days Actual amount=? - The ratio 4

The ratio of two number is 5:4 if 40% of the first number is 12, what will be 50% of the second number? - The pool

There is 210 l of water in the pool. If you know that the pool is 30% full, calculate how many liters of water will fit into it? - Metal washers

Metal washers with a diameter of 80 mm are cut from a strip of steel sheet with a width of 10 cm and a length of 2 m. Calculate the percentage of material waste if no material is lost when two adjacent circles meet. - Pharmacist

The pharmacist had a 12 l vessel herbal lotion, which contained a 30% active ingredient. Her assistant poured 18 liters of herbal lotion containing 45% of the active ingredient into a container. What percentage of herbal lotion was produced? - Lions

If 8 lions is 40% how many would 75% be? - 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%? - Iglu - cone tent

The cone-shaped tent is 3 m high, the diameter of its base is 3.2 m. a) The tent is made of two layers of material. How many m² of fabric is needed for production (including flooring) if 20% needs to be added to the minimum amount due to cutting waste? b) - 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 - A 36

A 36 g sample of the substance contains 91% water. After drying, the weight of the sample was reduced to 18 g. What percentage of water is now in the sample? - Decibel

By what percentage does the sound intensity increase if the sound intensity level increases by 1 dB? - How many

How many m² of copper sheet is needed to replace the roof of a conical tower with a diameter of 13 meters and a height of 24 meters if we count 8% of the material for bending and waste? - 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? - Traffic sign

There is a traffic sign for climbing on the road with an angle of 7%. Calculate at what angle the road rises (falls). - 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

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Our percentage calculator will help you quickly calculate various typical tasks with percentages. Expression of a variable from the formula - practice problems. Percentages practice problems.