# Units - examples - page 77

1. Bags
The first bag has a weight of 18 kg, the second bag is a one-third lighter than the first and the third bag has three times less the weight of all three bags together. Determine their weights.
2. Novak
Novak needed to dig up three of the same pit in the garden. The first pit dug father alone for 15 hours. His second dig son helped him and it did that in six hours. The third pit dug son himself. How long it took him?
3. Cuboid enlargement
By how many percent increases the volume of cuboid if its every dimension increases by 30%?
4. Cuboid surface
Determine surface area of cuboid if its volume is 52.8 cm cubic and length of the two edges are 2 cm and 6 cm.
5. Working together
One painter paint the nursery in 10 days, the second in 8 days. How many days will the nursery be painted if they work together?
6. Cars 6
At 9:00 am two cars started from the same town and traveled at a rate of 35 miles per hour and the other car traveled at a rate of 40 miles per hour. After how many hours will the cars be 30 miles apart?
7. Water reservoir
The reservoir shape of a cylinder having a diameter 8 m and a height 2.8 m. The device indicates that the reservoir contains 800 hectoliters of water. Calculate how much % of volume is used.
8. Family
Son is 3/5 smaller than the mother. Mother is 99 cm higher than the son. How tall is the mother?
9. Angles in ratio
The size of the angles of the triangle are in ratio x: y = 7: 5 and the angle z is 42° lower than the angle y. Find size of the angles x, y, z.
10. Scale 3
Miriam room is 3.2 meters wide. It is draw by line segment length 6.4 cm on floor plan. In what scale it is plan of the room?
A domed stadium is in the shape of spherical segment with a base radius of 150 m. The dome must contain a volume of 3500000 m³. Determine the height of the dome at its centre to the nearest tenth of a meter.
12. Four friends
Four friends shared the money. Vasek got 1/4 of the total amount. Tonda received 1/3 of the rest of the money, Joe got a half from the second residue and Jirka left 80. How much money get together?
13. Breeder
Seven hens breeder has supplied 350 eggs. How long can deliver, if each of its chickens can withstand at least 5 eggs for week?
14. Axial cut
The cone surface is 388.84 cm2, the axial cut is an equilateral triangle. Find the cone volume.
15. Remuneration
Total remuneration for workers is 47 000 CZK. The second worker received 20% more than the first and third 4000 CZK less than a second employee. How many CZK each received?
16. Conva
How many liters of water fit into the shape of a cylinder with a bottom diameter 20 cm and a height 45 cm?
17. Masons
1 mason casts 30.8 meters square in 8 hours. How long casts 4 masons 178 meters square?
18. Potatoes 6
The farmer brought potatoes to the market. In the first hour he sold two-fifths of the potatoes brought, in the second hour he sold five-sixth of the remaining potatoes, and in the third hour he had sold the last 40kg of potatoes. How many kg of potatoes d
19. Garden
The garden has a rectangular shape with lengths of 25 and 40 meters. It has been expanded so that each of its size increased by one fifth. How many square meters increased its acreage?
20. Tailor
Tailor bought 2 3/4 meters of textile and paid 638 CZK. Determine the price per 1 m of the textile.

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