Mass + percentages - math problems

Mass is a property of a physical body and a measure of its resistance to acceleration (a change in its state of motion) when a force is applied. An object's mass also determines the strength of its gravitational attraction to other bodies. The basic SI unit of mass is the kilogram (kg). Other are gram, tonne, milligram, etc.

Number of problems found: 76

Mixture
How many percentages mixtures do we get by adding 23ml of matter to 89ml of water?
Crystal
The crystal grows every month 1.2 permille of its mass. For how many months to grow a crystal from weight 177 g to 384 g?
Barrel of oil
Barrel of oil weighs 283 kg. When it mold 26% oil, weighed 216 kg. What is the mass of the empty barrel?
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?
Electric cooker
During which time t does an electric cooker with power input P = 500 W and with efficiency n = 75% heat water with mass m = 2 kg and temperature t1 = 10°C to the boiling point (t2 = 100°C). The specific heat capacity of water is c = 4 180 J. Kg-1. K-1
Radioactive material
A radioactive material loses 10% of its mass each year. What proportion will be left there after n=6 years?
Cacao
Cacao contains 34% filling. How many grams of filling are in 130 g cacao.
Butter fat
A quarter of kg butter contains 82% fat. How many grams of fat are in four cubes of butter?
Water percent
A 15 g sample of the substance contains 70% water. After drying, the weight was reduced to 9 g. What percentage of water is now in the sample?
Carrot seed
Carrot seed germination is 85%, weight 1000 carrots seeds are 2.4g. How many seeds are likely to germinate if we sow 8g of seeds?
Meat loses
Meat loses 18% of its weight by smoking. How much raw meat butcher used to manufacture 35 kilos of smoked?
Potatoes
Potatoes contain 78.6% starch. How many potatoes need to obtain 27 kg of starch?
Mushrooms
Mushrooms lose 90% by weight drying. How many fresh mushrooms are needed for 5 kg of dried mushrooms?
Drying apples
By drying, apples lose 85% of their weight. How many kgs of dried apples do we get from 820 kilograms of fresh?
Bakery
How heavy must prepare bread at a bakery if lose during baking 16% of water and after baking must have 2 kg? (Calculate to the nearest gram)
Weightlifter
Weightlifter lifted 75% of its weight. Determine how much weight lifted when he weighs 132 kg.
Metal alloy
What is the ratio of metals in the alloy that is in the 50 tonnes of steel to 30 kg nickel?
Mixture 2
How many liters of water must be added to 7 liters of a 20% solution to obtain a 10% solution?
Water in body
Water in the human organism of all the compounds represented, constitutes about 3/5 of the total weight. How many kilograms of water is in your body when you weigh 51 kg?
Apple variete
This year, my uncle harvested 350 kg of apples, including 105 kilograms of Ontario, and the rest is Jonathan. Determine what percentage of the Jonathan apples.