# Examples for 9th grade - page 32

- Bronze, tin and copper

Bronze is an alloy of tin and copper. An alloy of 10% tin and 90% copper is Gunmetal. If it contains 20% tin and 80% copper, it is bell metal. How many tons of molten bell metal and how many tons of copper is needed to make 100 tons of Gunmetal? - Circles

In the circle with a radius 7.5 cm are constructed two parallel chord whose lengths are 9 cm and 12 cm. Calculate the distance of these chords (if there are two possible solutions write both). - TV diagonal

Diagonal TV is 0.56 m long, how big the television sreen is if the aspect ratio is 16:9? - Circle sector

Circular sector with a central angle 10 ° has area 254 cm^{2.}Calculate its radius r. - Lathe

Calculate the percentage of waste if the cube with 52 cm long edge is lathed to cylinder with a maximum volume. - Scale

Cylinder was drawn in scale 7:1. How many times is the volume of the cylinder smaller in reality? - Function

For linear function f(x) = ax + b is f(12)=118; f(15)=132. Calculate m, if f(m) = 2005 . - The camp

At the end of the camp a 9 friends exchanged addresses. Any friend gave remaining 8 friends his card. How many addresses they exchanged? - Cosine

Calculate the cosine of the smallest internal angle in a right-angled triangle with cathetus 19 and 4 and with the hypotenuse 19.416. - Rectangular trapezoid

The rectangular trapezoid ABCD is: /AB/ = /BC/ = /AC/. The length of the median is 6 cm. Calculate the circumference and area of a trapezoid. - Baker

The baker makes from 10 kg of flour 12 kg dough. How much flour he need to make a 100 kg dough? - Against each other

From two points A, B distant 45 km at the same time started two cars against each other at speeds 81 km/h and 67 km/h. How long does cars meet and what distance passes each of them? - Arc

Convert to arc measures (radians): 1367 ° Result write as a multiple of π - Two cars

Car A1 goes at average speed of 133 km/h and the second car A2 goes at 128 km/h. How many second will it take car A1 to circulate car A2? Assume that both cars are 4.7 meters long and the safety gap between cars is 2.7 meters. - Brass tube

The outer perimeter of brass tube (ρ = 8.5 g/cm^{3}) is 51 cm. Its mass is 5 kg, length 56 cm. What is the pipe wall thickness? - Triangle

Calculate the area of the triangle ABC if b = c = 20 cm, R = 21 cm (R is the circumradius). - Summerjob

Albert, Beny, Cyril and Dan worked on summerjob. From the total revenue Albert received 2/5, Beny 1/6 , 3/10 Cyril and Dan the rest which is 324 euros. How many euros earned every one of them? - Logs

The log has diameter 30 cm. What's largest beam with a rectangular cross-section can carve from it? - Railways - golden parachutes

As often happens in Slovakia habit, the state's financial institution which takes from poverty and gorilas give. A hardworking punishing taxes. Let's look at a short work of director Railway Company ZSSK - Mgr . P. K. : 18 months 'work' as director r - Angle

A straight line p given by the equation ?. Calculate the size of angle in degrees between line p and y-axis.

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