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maths formula

Average formula:

Let a1,a2,a3,......,an be a set of numbers, average = (a1 + a2 + a3,+......+ an)/n

Fractions formulas:













Converting a mixed number to an improper fraction:




Converting an improper fraction to a mixed number:




Formula for a proportion:




In a proportion, the product of the extremes (ad) equal the product of the means(bc),

Thus, ad = bc

Percent:

Percent to fraction: x% = x/100

Percentage formula: Rate/100 = Percentage/base

Rate: The percent.
Base: The amount you are taking the percent of.
Percentage: The answer obtained by multiplying the base by the rate

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:

Perimeter:

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

Perimeter of a rectangle: l + w + l + w
l: le…