# Equation - examples - page 14

1. Cows
20 cows has food for 60 days. We reduce the dose to two-thirds for 18 cows. How many days will be fed?
2. Sum-log
The sum of two numbers is 32, the sum of their logarithms (base 10) is 2.2. Determine these numbers.
3. Brothers and sisters
Lenka has as many brothers as sisters. Her brothers have twice as many sisters as brothers. How many brothers and sisters are in the family?
4. Czech crown salary
The monthly salary of the employee is CZK 10,800. In the course of the year the bulk salary increased by CZK 500. Calculate which month (1 ... 12) was increased if its annual income was 133,600 CZK.
5. Soup
On Monday we cook 25 pots and 10 boilers of soup. On Tuesday 15 pots and 13 boilers. On Wednesday 20 pots and on Thursday 30 boilers. On Monday and Tuesday was cooked the same amount of soup. How many times more soup cooked on Thursday than on Wednesday?
6. Electrics - conductor
The wire is 106 meters long at 0 °C and at every temperature increase of 1 °C the length increases by 0.15 mm per 1 m length of wire. Determine a function which represents the overall length of the wire as a function of temperature. What is the length of t
7. Clock hands
The hands on the clock shows the time 12 hours and 2 minutes. Calculate the size of a sharp angle between clock hands three hours later.
8. Unknown number
Samuel wrote unknown number. Then he had add 200000 to the number and the result multiply by three. When it calculated he was surprised, because the result would have received anyway, if write digit to the end of original number. Find unknown number.
9. Clouds
From two points A and B on the horizontal plane was observed forehead cloud above the two points under elevation angle 73°20' and 64°40'. Points A , B are separated by 2830 m. How high is the cloud?
10. Pedestrian and the cyclist
Pedestrian and cyclist went against each from the two cities that are distant 40 km. Pedestrian started 30 minutes before the cyclist and walk an average speed of 5 km/h. What speed went cyclist when met after 120 minutes from the start of the pedestrian?
11. Function
For linear function f(x) = ax + ​​b ‬ is f(14)=179; f(15)=154. Calculate m, if f(m) = 2019 .
12. Square
If we increase one side of square by its one-half then square perimeter increase by 10 cm. What is the side of the square?
13. Drive
At the bus stop 8 people take out and 10 people take into bus. Next stop 6 take out and 5 take in. On the third stop 6 take out and 3 take in. The bus traveled further with 39 people. How many passengers were originally at the bus?
14. Variations 3rd class
From how many elements we can create 13,800 variations 3rd class without repeating?
Tree perpendicular to the horizontal surface has a shadow 8.32 meters long. At the same time meter rod perpendicular to the horizontal surface has shadow 64 cm long. How tall is tree?
16. Louvers
The company charges for office equipment louvers total 262 Eur. From the delivery bill is obvious that the louvers are 76 Eur expensive than their installation. What percentage of the total charged is the installation of louvers?
17. Painting rooms
If Dano paint three hours daily given work he complete in 7.5 days. How many hours a day would have to work to finish the job 1.5 days earlier?
18. Special cube
Calculate the edge of cube, if its surface and its volume is numerically equal number.
19. Father and son
Father is 48 years old, son 23. When will be the father twice older than a son?
20. Bus stop
Determine at what time the bus leaves from the bus stop outside the village, if you know that when you leave home at 8:00 and go at speed 3 km/h, you come to a stop 9 minutes after the departure of the bus, and when you go speed at 4 km/h, you come to the

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