Mass + percentages - practice problems
Number of problems found: 195
- Exp decay
An element with a mass of 780 grams decays by 16.3% per minute. How much of the element is remaining after 16 minutes, to the nearest 10th of a gram? - Apples 29
In a fruit market, apples are currently £4 per kilogram. If you buy ten kilograms of apples, you will receive three-tenths of the total price. How much will you pay for ten kilograms of apples at the market? - A chemist 2
A chemist has two alloys of bronze, one that is 12% tin and 88% copper and a second that is 10% tin and 90% copper. If these two alloys are melted and thoroughly mixed together, between what two values are the percent of tin in the mixture? - Peter 17
Peter ate 9 ounces of chocolate cake which was 75% of the entire cake. Which expression can be used to find the size of the full cake?
- Heat energy
Energy is measured using the unit Joule (J). Temperature is measured using the unit degree Celsius °C). To increase the temperature of 1 liter of water by 1°C, 4200 J of heat energy is required. (a) Kelly wants to increase the temperature of 2 liters of w - Cheap chocolate
Lucy's chocolate bar is 29% cocoa. If the weight of the chocolate bar is 100 grams, how many grams of cocoa does it contain? Round your answer to the nearest tenth. - Original 83173
When drying, the modeling mass loses 36% of its original volume. If the cube's volume is 5.12 dm³ after drying, what was the original length of the edge? - Represents 82661
The weight of the car with cargo is 7610 kg. The car's weight represents 23% of the car's total weight with cargo. What is the weight of the cargo? - Grinding 82435
We get 80 percent flour by grinding grain. How much grain do we need to grind to get 400 kg of flour?
- Semi-skimmed 82206
The dairy produces semi-skimmed milk (with 1.5% fat content) by skimming part of the fat from full-fat milk (with 4% fat content). 1 ton of semi-skimmed milk is produced from how many kilograms of fat milk? - Evaporating 81430
Sea water contains 3.4% salt. How much salt do we get by evaporating 25 kg of seawater, and how much water evaporates? - Produced 81413
A cube of sugar weighs 6 grams. How many sugar cubes are produced from one sugar beet that weighs 0.9 kg; if its sugar content is 18 percent? - Solution mixtures
We have 1 liter of 80% solution. Every hour, pour 1 dl of the solution, add 1 dl of water (a 0% solution), and mix. What percent solution will we have after two mixings? - Transported 80813
Three Tatras transported 22.2 tons of sand. The second Tatra transported 20% more than the first, and the third Tatra 25% more than the second. How much did each Tatra take?
- Fertilizer 80787
The fertilizer contains 15.8% nitrogen. Calculate the mass of fertilizer that must be added to the soil to make 17.0 g of nitrogen effective. Addition losses are 6.60%. - Hibernation 80718
The bear weighed 410 kg at the beginning of winter and lost 10 percent during hibernation. He gained 10 percent of his weight from spring to fall. Find out if the bear's weight was greater at the beginning of winter or autumn by what percentage. - Approximately 80443
The 94 m² flower bed is to be planted with begonias. An area of 2 dm² is needed for one seedling. How many grams of seeds should be sown if 1 g of seeds contains approximately 5000 seeds? Losses when growing seedlings are usually 30%. - Average 80442
The daily need for fat for a person is 80g on average. Almonds contain 45% fat. How many grams of almonds would a person have to eat if he wanted to cover his daily need for fats by eating only almonds? - Contains 80440
Cow's milk contains an average of 3.6% fat. How many liters of milk are needed to make 250g of butter? Butter contains 82% fat.
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