# Problems for 6th grade (the sixth graders) - page 11

1. Rounding 2 Round the following negative number: -143.021
2. Car amortization Assume that the car has a life 13 years and new cost 24000 euros. Calculate how much a month is amortized cost of the car over its lifetime. Amortization is the gradual reduction of assets (cars, buildings), mainly due using or aging.
3. Wood Peter chops wood. If they cut down a half hours a day he ended work in 9 days. But Peter needs to end work 3 days earlier. How many minutes a day should cut down?
4. Tablecloth I embroider tablecloth in 20 days but if I embroider 3/4 hours a day I have embroider it for 15 days. How long do I embroider a day?
5. Rounding Double round number 727, first to tens, then to hundreds. (double rounding)
6. Eggs Mother bought from neighbors 39 domestic eggs. Her neighbor got back €4.54 from €10. How many euros get back from 20 banknote if she buy 94 eggs from a neighbor?
7. Math test In class 6.A are 26 students and the teacher had managed to give tests to 13 students. 13 testes he gave in 6.5 min. How many pupils still haven't test? How long will it take techer to give tests to 43 students?
8. Divisibility Determine all divisors of number 84.
9. Stones in aquarium In an aquarium with a length 2 m; width 1.5 m and a depth of 2.5 m is a water level up to three-quarters of the depth. Can we place stones with a volume of 2 m3 into the aquarium without water being poured out?
10. Number train The numbers 1,2,3,4,5,6,7,8 and 9 traveled by train. The train had three cars and each was carrying just three numbers. No. 1 rode in the first carriage, and in the last carriage was all odd numbers. The conductor calculated sum of the numbers in the first
11. Honza + Alice + Tonda Honza + Alice + Tonda have a total of 111 USD. The ratio between Honza and Alena is 5:6 and the ratio between Alice and Tonda is 4:5 How many money have each of them?
12. Crown Siblings collect a 2-crowns and 5-crowns. Together have 80 coins with a total of value 310 crowns. How many saved two-crowns and how many five-crowns?
13. Cuboid 5 Calculate the mass of the cuboid with dimensions of 12 cm; 0.8 dm and 100 mm made from spruce wood (density = 550 kg/m3).
14. Apples Mr. Vesely give to the market his own 48 kg of apples, 40 kg from Mr. Kovar and 72 kg of Mr. Novak. Grossed a total of 1,920 CZK. How must divide income money for apples?
15. Forest ranger Forest ranger watching from the hide deers. At one time point he can see 6 deers. How many maximum deers can be see by 3 rangers at same time?
16. Divers 20-member group of divers carries the air for 15 hours of diving. 4 members of the expedition sick or wasn't came. How many hours is sufficient air to other divers?
17. Aquarium II Calculate how much glass we need to build an aquarium with a rectangular shape with base 70 cm × 70 cm and a height of 70 cm, if the waste is 2%. Aquarium haven't top glass.
18. Cast brass Brass cast weight was 3.84 kg, it had turned into piston weight 3.491 kg. How many grams of brass was turned off?
19. Granite cube What is the weight in kg granite cube with an edge of 0.5 m if 1dm3 of granite weight 2600 g?
20. Playground Rectangular playground is fenced with 38 m long netting. Its width is 7 m. Calculate its length.

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