Question

Suppose that 18 inches of wire cost 72 cents At the same rate, how much (in cents) will 13 inches of wire cost?

Answer 1

So right now in the the given question we use the proportional method

In this case the proportion used is inverse

What is Inverse Proportion ?

In direct proportion, if one quantity is increased or decreased then the other quantity increases or decreases, respectively. But in indirect or inverse proportion, if one quantity increases then other quantity decreases and vice-versa.

Eg: As the variable y decreases the variable x will also decrease

When we apply the given values into a fraction we get

`(18)/(72) = (13)/(x)`

Cross Multiplying we get,

`18x = 72X13`

`18x = 936`

`x = (936)/(18)`

`x = 52`

Hence, 13 inches of wire costs 52 cents