# Expression of a variable from the formula - 7th grade (12y) - math problems

#### Number of problems found: 238

• Two thirds Find two-thirds of the number equal to two-thirds of 99
• Simple sequence Continue with this series of numbers: 1792,448, 112, _, _ Determine the radius of the circle, if its perimeter and area is the same number.
• Sum of four numbers The sum of four consecutive natural numbers is 114. Find them.
• Cross five The figure on the picture is composed of the same squares and has a content of 45cm². What's its perimeter?
• Greg and Bill Greg is 18 years old. He is 6 less than 4 times Bill's age. How old is Bill?
• Car and cyclist Cyclist started from town at speed 18 km/h. After 1 hour 30 min started the car from town and caught up with the cyclist in 50 minutes. How fast was a car?
• Interior angles Calculate the interior angles of a triangle that are in the ratio 2: 3: 4.
• One and a half chicken One and a half chicken bears one and a half egg in one and a half day. How many eggs can withstand from 6 chicken in 6 days?
• Circle chord Calculate the length of the chord of the circle with radius r = 10 cm, length of which is equal to the distance from the center of the circle.
• Volume of sphere How many times does the volume of a sphere increase if its radius increases 2 ×?
• Find the Find the radius of the circular base of the vessel, whose perimeter is 2.51 m. Write the result to one decimal place in meters. Via the π sign - Ludolph's number
• Cube edge Determine the edges of the cube when the surface is equal to 37.5 cm square.
• Cone from cube The largest possible cone was turned from a 20 cm high wooden cube. Calculate its weight if you know that the density of wood was 850 kg/m3
• Cube edges The sum of the lengths of the cube edges is 42 cm. Calculate the surface of the cube. How many times does the surface of a sphere decrease if we reduce its radius twice?
• Unknown number 24 f we add 20, we get 50% of its triple. What is this unknown number?
• Alley Alley measured a meters. At the beginning and end are planted poplar. How many we must plant poplars to get the distance between the poplars 15 meters?
• Diameter What is the inside diameter of the cylinder container and if half a liter of water reaches a height 15 cm?
• Raspberries Dano had 20 raspberries. John had 90% more raspberries than Dano. Determine how many raspberries have Dano and Juraj together.

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