# Examples for 9th grade - page 50

- Annual income

The annual incomes (in thousands of $) of fifteen families is: 60, 80, 90, 96, 120, 150, 200, 360, 480, 520, 1060, 1200, 1450, 2500, 7200 Calculate harmonic and geometric mean. - The city

In the city is 2/4 of women married to 3/4 men. What percentage of townspeople is single (not married)? - Welders

Welder do the job for six hours, the second one for 8 hours. How long do the job third welder if all together can do job in 2 hours? - Square ABCD

Construct a square ABCD with cente S [3,2] and the side a = 4 cm. Point A lies on the x-axis. Construct square image in the displacement given by oriented segment SS'; S` [-1 - 4]. - Sputnik

The first Earth satellite was flying at speed 8000 m/s. At that rate he circled the earth in 82 minutes. Jet flies at an average speed 800 km/h. How long would it take circle the earth round? - The creek

Workers cleaned the creek within 3 days. The first day cleanse one-fifth the length of the creek, the next day 40% of the length of the stream and the third day 8 km length of the creek. How long is a creek? - Win in raffle

The raffle tickets were sold 200, 5 of which were winning. What is the probability that Peter, who bought one ticket will win? - Juice box 2

Box with juice has the shape of a cuboid. Internal dimensions are 15 cm, 20 cm and 32 cm. If the box stay at the smallest base juice level reaches 4 cm below the upper base. How much internal volume of the box fills juice? How many cm below the top of the - Hockey game

In the hockey game was made 6 goals. Czech played against Finland. Czechs won 4:2. In what order to fall goals? How many game sequence was possible during the game? - James

James paints a fence. If every day instead of 14 planks painted 16 would be done on one day earlier. How many of planks has a fence altogether? - Saw

Blade circular saw with a diameter 42 cm turns 825 times per minute. Expresses his cutting speed in meters per minute. - Water well

Drilled well has a depth 20 meters and 0.1 meters radius. How many liters of water can fit into the well? - Sisters

Sisters Zuzka Lenka and Vierka has save for a new bike. Zuzka save € 90, Lenka save € 90 and Vierka save € 82. Missing 30% gave them their mother. What is the price of the bike? - Cleaners

Milan would clean up the room for 2.5 hours, Eric would take 10 hours. How long they swept the room together? - Prism

The base of a perpendicular triangular prism is a right triangle with legs 4.5 cm and 6 cm long. What is the surface of the prism, if its volume is 54 cubic centimeters? - Equation

How many real roots has equation ? ? - Trapezium

The area of trapezium is 35cm^{2}find its altitude if the bases are 6cm and 8cm. - Copper plate

Calculate the thickness of the copper plate with a density 8.7 g/cm³ measuring 1.5 meters and 80 cm and its weight is 3.65 kg - Circle and hexagon

Calculate the radius of a circle whose circumference is 8.4 cm longer than the circumference of the inscribed regular hexagon. - Surveyor

Calculate the area of what may vary rectangular, if it focused by surveyor and found the dimensions 18 x 15 m while in each of the four joint points can be position deviation 25 cm?

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