How many ml 30% of peroxide (H2O2) should be poured into 100ml H2O to give a 20% solution?
Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):
Showing 0 comments:
Be the first to comment!
To solve this example are needed these knowledge from mathematics:
Next similar examples:
Sea water containing 5% salt. How many kg of fresh water necessary to pour into 40 kg of sea water so that the salinity fell to 2%?
- Acid solution
By adding 250 grams of a 96% solution of sulfuric acid to its 3% solution its initial concentration was changed to 25%. How many grams of 3% of the acid were used for dilution?
- CuSO4 mixture
How many grams of solid CuSO4 we have to add to 450g of 15% CuSO4 solution to produce a 25% solution?
How 0.5 liters of 8% vinegar diluted to a concentration of 20 hundredths % of vinegar? How many liters of water must be pour?
- Apples 2
Dried apples contain 15% water. Fresh apples contain 80% water. How many kg of apples we need buy in order to get 3 kg of dried apples?
- The ball
The ball was discounted by 10 percent and then again by 30 percent. How many percent of the original price is now?
- Sale discount
The product was discounted so that eight products at a new price cost just as five products at an old price. How many percents is the new price lower than the old price?
Calculate how many % is the number 26.25 less than the number 105.
The children's competition was attended by 63 girls, which is 30% of all children's participants. How many children attended this competition?
- Profit gain
If 5% more is gained by selling an article for Rs. 350 than by selling it for Rs. 340, the cost of the article is:
- The price
The price of the land increased by 17%. What was the original price of the land if it now costs 46800 €?
- Finding the base
Find unknown base of percent: 12.5 percent of what = 16 ?
In the first round of slalom fell 15% of all competitors and in the second round another 10 racers. Together, 40% of all competitors fell. What was the total number of competitors?
How much of a mixed forest rangers want to cut down, if their head said: "We only cut down pine trees, which in our mixed forest 98%. After cut pine trees constitute 94% of all trees left."
- Theorem prove
We want to prove the sentense: If the natural number n is divisible by six, then n is divisible by three. From what assumption we started?
- Fifth of the number
The fifth of the number is by 24 less than that number. What is the number?
- Sale off
Product cost 95 euros before sale off. After sale off cost 74 euros and 10 cents. About what percentage of produt became cheaper?