# Ratio + percentages - examples

On solving problems and tasks with proportionally we recommend hint rule of three. Rule of three (proportionality) help solve examples of direct and inverse proportionality. Three members makes possible to calculate the fourth - unknown member.

1. Bonus
Gross wage was 527 EUR including 16% bonus. How many EUR were bonuses?
2. River
Calculate how many promiles river Dunaj average falls, if on section long 957 km flowing water from 1454 m AMSL to 101 m AMSL.
3. Server
Calculate how many average minutes a year is the web server is unavailable, the availability is 99.99%.
4. Blood
In human body the blood is about 7.2% body weight. How many kilograms of blood is in the human body with weight 93 kg?
5. Inflation
What is better for people (employees)? ?
6. Tanks
Fire tank has cuboid shape with a rectangular floor measuring 13.7 m × 9.8 m. Water depth is 2.4 m. Water was pumped from the tank into barrels with a capacity of 2.7 hl. How many barrels were used, if the water level in the tank fallen 5 cm? Wr
7. Gutter
How much metal is needed for production 46 pieces of gutter pipes with the diameter 12 cm and length of 4 m? The plate bends add 2% of the material.
8. Sea water
Seawater contains about 4.3% salt. How many dm3 of distilled water we must pour into 5 dm3 of sea water to get water with 1.8% salt?
9. Climb in percentage
The height difference between points A and B is 475 m. Calculate the percentage of route climbing if the horizontal distance places A, B is 7.4 km.
10. Tare
Gross weight of shipment is 5188 kg and its tare is 5.6%. Calculate the net weight of the shipment.
11. Expansion
If one side of the rectangle is larger 4-times and second 2-times, what percentage increases the area of rectangle?
12. Lathe
From the cube of edge 37 cm was lathed maximum cylinder. What percentage of the cube is left as waste after lathed?
13. Bureau of Labor
Bureau of Labor is a state institution that provides mike and the rest for their so-called clients. The mission of the Bureau of Labor is spend taxpayer money to provide relaxation and benefits to those who do not want to work. Popularly speaking sense the
14. VAT
John paid 100 Euros in store for purchase. Calculate value added tax (VAT), which paid in purchase, if the VAT rate is 20%.
15. TV fail
The TV has after 10,000 hours average 25 failures. Determine the probability of TV failure after 200 hours of operation.
16. Saving
Allen save € 2860 to buy a car. Yet it lacks save 55% of the car price. How much is the car?
17. Acid
The barrel is 199 litres of 38% acid. How many percent acid occurs when 61 litres revoke and replace it with the same amount of water?
18. Tape
Video is 153% more expensive than tape recorder. How many percent is tape recorder less expensive than video?
19. Profitable bank deposit 2012
Calculate the value of what money lose creditor with a deposit € 9500 for 4 years if the entire duration are interest 2.6% p.a. and tax on interest is 19% and annual inflation is 3.7% (Calculate what you will lose if you leave money lying idle at negative
20. Discount
Product has been discounted twice by 19%. What is the total discount given?

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