Inverse Cross Multiplication

Calculator and formulas for calculating the inverse cross multiplication


Inverse cross multiplication is a method of elementary arithmetic to calculate the value of a variable in an equation involving two multiplications or rational expressions (not to be confused with inverse cross product).

To perform the calculation, enter three values, then click on the 'Calculate' button.


Inverse cross multiplication

 Variable a   Variable b
=
 Variable c   Result x
Decimal places

Formula and Example


The formula for the reverse cross multiplication consists of two pairs of values, the multiplication gives the same value.

\(\displaystyle a· b=c· x\)

The formula is changed for the calculation:

\(\displaystyle x=\frac{a ·b}{c}\)

Example


If 4 workers complete a job in 20 hours, how long does it take 5 workers?
\(\displaystyle 4 · 20=5 · x\)
\(\displaystyle x=\frac{4 ·20}{5} = 16 \;hrs.\)

Absolute ChangeAll divisors of an integerAverageBinomial formulasCommon divisors of two integersConsecutive integersCross multiplicationDiamond problemDigit sumDigital rootDirect variationDivision with remainderElementary arithmeticFactorialFOIL MethodInverse cross multiplicationInverse moduloGreatest common divisorLeast common multipleModuloMultiplicative inverseRelative Change


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