# Percentages + weighted average - math problems

#### Number of problems found: 13

• Unemployment rate
Over the last 16 years, the country's unemployment rate has changed according to the following frequency table: years of unemployment: 2 5 2 3 3 1 unemployment rate: 0.5 1 1.5 2 2.5 3 in % (percent). Determine the two-sided confidence interval for the var
• 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?
• 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
• Corona virus
Calculate an estimate of the percentage of GDP (Gross Domestic Product) declined due to the quarantine related to the corona COVID-19 virus that lasts for 2 months, during which time the economic activity is down by 80%.
• Final exam
There are 5 learners in a class that has written a final exam Aleta scored 55% vera scored 36% and Sibusiso scored 88% if Thoko scored 71% and the class average was 63%. What was Davids score as a percentage?
• Peroxide
How many ml should we pour 30% of peroxide (H2O2) into 100ml H2O to give a 20% solution?
• CuSO4 mixture
How many grams of solid CuSO4 we have to add to 450g of 15% CuSO4 solution to produce a 25% solution?
• Mixture 2
How many liters of water must be added to 7 liters of a 20% solution to obtain a 10% solution?
• Pharmacy
The pharmacy adds to 3 liters of 95-percent alcohol 5 liters of 38.04 percent alcohol. How much percent alcohol the pharmacy got?
• Kerosine and petrol
If 4 liters of petrol containing 15% kerosine are added to another 7 liters of petrol containing 10% kerosine, what percentage of the petrol is kerosine?
• Hydrochloric acid
Determine the concentration of which must have a solution of hydrochloric acid that mixing 10 l of the solution with 8 liters of 26% solution to get the solution with a concentration of 50%?
• Vinegar
What percentage vinegar we get if we mix 1 if dm³ eight percent vinegar with 1.5 dm³ six percent vinegar?
• Vinegar 2
How many percentages of vinegar solution will we get if we mix 3.5 liters of 5.8% and 5 liters of 7.6% vinegar?

We apologize, but in this category are not a lot of examples.
Do you have an exciting math question or word problem that you can't solve? Ask a question or post a math problem, and we can try to solve it.

We will send a solution to your e-mail address. Solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Our percentage calculator will help you quickly calculate various typical tasks with percentages. Percentages Problems. Weighted average - math problems.