# Expression of a variable from formula - examples - page 22

- Population growth

How many people will be on Earth from two people for 5,000 years, if every couple has always 4 children, (2 boys and 2 girls) at the age of 25-35, and every man will live 75 years? - Height as diameter of base

The rotary cylinder has a height equal to the base diameter and the surface of 471 cm^{2}. Calculate the volume of a cylinder. - Edges or sides

Calculate the cube volume, if the sum of the lengths of all sides is 276 cm. - Exponential warm

Suppose that a body with temperature T1 is placed in surroundings with temperature T0 different from that of T1. The body will either cool or warm to temperature T(t) after time t, in minutes, where T(t)=T0 + (T1-T0)e^(-kt) . If jello salad with 30 degre - A cylinder

A cylinder 108 cm high has a circumference of 24 cm. A string makes exactly 6 complete turns around the cylinder while its two ends touch the cylinder's top and bottom. (forming a spiral around the cylinder). How long is the string in cm? - AP RT triangle

The length of the sides of a right triangle form an arithmetic progression, longer leg is 24 cm long. What are the perimeter and area? - Geometric progression

In geometric progression, a1 = 7, q = 5. Find the condition for n to sum first n members is: sn≤217. - Calculate

Calculate the length of a side of the equilateral triangle with an area of 50cm^{2}. - Perimeter of base

The circumference of the base of the rotating cylinder is same as its height. What is the diameter and height of this cylinder with volume 1 liter? - Girls

The boys and girls in the class formed without the rest of the fives, 2 girls and 3 boys. There are 6 girls missing to create mixed pairs (1 boy and 1 girl). How many girls are in the classroom? - Deviation of the lines

Find the deviation of the lines AG, BH in the ABCDEFGH box-cuboid, if given | AB | = 3cm, | AD | = 2cm, | AE | = 4cm - Guppies

Audrey has some guppies in a fish tank. The ration of the oranges guppies to silver guppies is 3:5. She has 12y oranges guppies. Write the number of silver guppies she has in terms of y - Square root 2

If the square root of 3m^{2}+22 and -x = 0, and x=7, what is m? - Meat loses

Meat loses 18% of its weight by smoking. How much raw meat butcher used to manufacture 35 kilos of smoked? - Two resistors

Two resistors when they give 25 ohms in series and 4 ohms in parallel what the values of - 3d printer

3D printing ABS filament with diameter 1.75 mm has density 1.04 g/cm^{3}. Find the length of m = 5 kg spool filament. (how to calculate length) - Spherical tank

The tank of a water tower is a sphere of radius 35ft. If the tank is filled to one quarter of full, what is the height of the water? - Diagonals of pentagon

Calculate the diagonal length of the regular pentagon: a) inscribed in a circle of radius 12dm; b) a circumscribed circle with a radius of 12dm. - Expressions 3

If k(x+6)= 4x^{2}+ 20, what is k(10)=? - Square

Calculate the area of the square shape of the isosceles triangle with the arms 50m and the base 60m. How many tiles are used to pave the square if the area of one tile is 25 dm^{2}?

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