# Expression of a variable from formula - examples - page 11

- Bus lines

Buses connections are started from bus stop on its regular circuit as follows: No. 27 bus every 27 minutes and No.18 every half hour. What time started this two bus lines run if the bus stop met at 10:15 am.? - Rotary bodies

The rotating cone and the rotary cylinder have the same volume 180 cm^{3}and the same height v = 15 cm. Which of these two bodies has a larger surface area? - Cuboid and ratio

Cuboid has dimensions in ratio 1:2:6 and the surface area of the cuboid is 1000 dm^{2}. Calculate the volume of the cuboid. - Billboard

Rectangular billboard is 2.5 m long with a diagonal 2.8 m long. Calculate the perimeter and the content area of the billboard. - Even / odd numbers

a / Using variable n write two consecutive odd numbers. b / the sum of three consecutive odd numbers is 333. What are this numbers? - Square and rectangle

Calculate the side of a square which content area equals area of the rectangle having a length of 3 cm greater and by 2 cm smaller than the side of the square. - Car consumption

The car has passed 988 kilometers and consumed 66 liters of petrol. What is the consumption per 100 kilometers? - Sides ratio

Calculate the circumference of a triangle with area 84 cm^{2}if a:b:c = 10:17:21 - Hollow sphere

The volume of the hollow ball is 3432 cm^{3}. What is its internal radius when the wall thickness is 3 cm? - Perimeter from area

What is the perimeter of the square if its content is 64 cm^{2}? - Unknown number 24

f we add 20, we get 50% of its triple. What is this unknown number? - Diagonal of the rectangle

Calculate the diagonal of the rectangle which area is 54 centimeters square and the circuit is equal to 30 cm. - 30-gon

At a regular 30-gon the radius of the inscribed circle is 15cm. Find the "a" side size, circle radius "R", circumference, and content area. - Disc

Circumference of the disk is 78.5 cm. What is the circumference of the circular arc of 32° on the disc? - Coins

Denis and Zdeno together have 97 coins. If Denis had 4 coins less than he has now, the number of the coins would be in the ratio 14: 17. Determine the number of coins owned by Denis and Zdeno. - Fuel economy

How many kilometers is sufficient petrol in the cylinder fuel tank with a diameter 40 cm and the base of tank length 1 m, when it is filled to 60% and if the car consume 15 liters per 100 km? - Two diagonals

The rhombus has a side length 12 cm and length of one diagonal 21 cm. What is the length of the second diagonal? - Unknown number 7

Calculate unknown number whose 12th power when divided by the 9th power get a number 27 times greater than the unknown number. Determine the unknown number. - Cuboid - ratios

The sizes of the edges of the cuboid are in the ratio 2: 3: 5. The smallest wall have area 54 cm^{2}. Calculate the surface area and volume of this cuboid. - Blueberries 2

Lenka and Martin collected eight liters of blueberries in two hours. How long will take to collect blueberries by Lenka itself, if we know that she collect all 2.5 hours less than Martin?

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