# Examples for 9th grade - page 46

1. Direct route
From two different places A and B connected by a direct route, Adam (from city A) and Bohus (from city B) started at a constant speed. As Adam continued to go from A to B, Bohus turned around at the time of their meeting and at the same speed he returned t
2. Probabilities
If probabilities of A, B and A ∩ B are P (A) = 0.62 P (B) = 0.78 and P (A ∩ B) = 0.26 calculate the following probability (of union. intersect and opposite and its combinations):
3. Rings groups
27 pupils attend some group; dance group attends 14 pupils, 21 pupils sporty group and dramatic group 16 pupils. Dance and sporting attend 9 pupils, dance and drama 6 pupil, sporty and dramatic 11 pupils. How many pupils attend all three groups?
4. Center of gravity
In the isosceles triangle ABC is the ratio of the lengths of AB and the height to AB 10:12. The arm has a length of 26 cm. If the center of gravity T of triangle ABC find area of triangle ABT.
5. Harvesters
The first harvester reaps the grain from land for 24 hours, the second harvester for 16 hours. For how many hours will take harvest by two harvesters, but the second harvester started working four hours later than the first?
6. Znojmo
From Znojmo to Brno started truck with a trailer at an average speed 53 km per hour. Against him 14 minutes later from Brno started car with an average speed of 1.2-times greater than the truck. How long and how far from Znojmo, they meet if the distanc
7. Product V2
The price of product was increased by 12%. Price increased by 273. How much money it would cost this product, if it was on the contrary by 19% discounted.
8. Weekly service
In the class are 20 pupils. How many opportunities have the teacher if he wants choose two pupils randomly who will weeklies?
9. Mukls
The working group, in which 6 workers would ordered job completed within 21 working days. How many workers must be accept yet that the contract will be completed in 14 working days?
10. Painters
One painter could paint a school for 7 days. The second one for 6 days. It was necessary to paint the school in two days. Next painter was invited and all worked together. How long would this painter painted the school itself?
11. Flowerbed
On the flowerbed was planted 280 flowers - pansies and crayons. During the first week wilts quarter of pansies and an eighth crayons, which is 20% of all flowers. How many pansies were planted on the flowerbed?
12. Coffee
Coffee merchant has coffee robusta and arabica species. 1 kg Robusta worth 450 CZK, Arabica 1 kg is 300 CZK more expensive. Calculate how many kilograms of Robusta and Arabica will need to produce 30 kg of the mixture so that the mixture cost is 490 CZK p
13. Glass
How many glass are needed to produce glass with base regular 5-gon if one base triangle in the base is 4.2 square cm and the height is 10 cm?
14. Influenza
For the first week of February by influenza 5% of children in kindergarten. The second week ill 9 next children, bringing the number of patients increased to 20%. How many children went to the kindergarten?
15. Coins
On coins found was stated that from the year 87 BC. It is right?
16. VAT
In the country XYZ car Daewoo Leganza costs 3748 Euros including VAT; 3335.72 Eur without VAT. a) Determine the rate of VAT. b) How much is Euro VAT paid on the purchase? c) How many % of the total price of the goods is VAT? VAT = value added tax.
17. Container
First day got off 1/4 water from full container, second day 1/5 of the remaining water. How many percent remain container filled?
18. Two tributaries
Two tributaries of the pool fill it in 10 hours. One of the tributaries would fill 15 hours. How long would fill the first tributary?
19. Angles
The outer angle of the triangle ABC at the vertex A is 114°12'. The outer angle at the vertex B is 139°18'. What size is the internal angle at the vertex C?
20. Antennas
If you give me two antennas will be same. If you give me again your two antenna I have a 5× so many than you. How many antennas have both mans?

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