## Percentage Formula :

Part/Whole = %/100

(or )

is/of = %/100 (or ) x/T = P/100 [T = Total amount, P = Percentage, x = Value]

(or )

% = (new value – original value)/100

Examples:

Q. 15 % of 3000 is____

A. x= ?, T = 3000, P = 15

x/T = P/100

x = (P X T)/100 = (15 X 3000)/100

x = 45000/100 = 450

So, 15 % of 3000 is 450

### Consumer math formulas:

Discount = list price × discount rate

Sale price = list price − discount

Discount rate = discount ÷ list price

Sales tax = price of item × tax rate

Interest = principal × rate of interest × time

Tips = cost of meals × tip rate

Commission = cost of service × commission rate

#### Geometry formulas:

##### Area:

Area of a square: s × s [s: length of one side]

Area of a rectangle: l × w [l: length, w: width]

Area of a triangle: (b × h)/2 [ b: length of base, h: length of height]

Area of a trapezoid: (b1 + b2) × h/2 [ b1 and b2: parallel sides or the bases, h: length of height]

##### Perimeter:

Perimeter of a square: s + s + s + s [ s:length of one side]

Perimeter of a rectangle: l + w + l + w [ l: length, w: width]

Perimeter of a triangle: a + b + c [a, b, and c: lengths of the 3 sides]

###### volume:

Volume of a cube: s × s × s [s: length of one side]

Volume of a box: l × w × h [l: length, w: width, h: height]

Volume of a sphere: (4/3) × pi × r3 [pi: 3.14, r: radius of sphere]

Volume of a triangular prism: area of triangle × Height = (1/2 base × height) × Height

[base: length of the base of the triangle, height: height of the triangle, Height: height of the triangular prism]

Volume of a cylinder: pi × r2 × Height

[pi: 3.14, r: radius of the circle of the base, Height: height of the cylinder]

And More Maths formulas