Question

If you spend $55 for transportation and clear $250 a month, what percent of your income do you spend on transportation?

Answer 1

`"$ 55 is 22% of $ 250"`

Explanation:

The problem asks:
`"55 is what percent of 250"`

You can translate that question into math language and get an equation that's easy to solve.

`"55   is   what percent   of   250"`

`55   =  color(white)(.....) (x)/(100)color(white)(.......)×   250`

`color(white)(..............)`―――――――

`55 = (x)/(100)× 250`    Solve for x, already defined as "the percent"

1) Clear the fraction by multiplying both sides by `100` and letting the denominator cancel
After you multiply and cancel, you will get this:
`5500 = x xx250`

2) Save yourself the trouble of doing the division by dividing both sides to make the numbers smaller

Start by dividing both sides by `10`
`550 = 25x`

Divide both sides by `5`
`110 = 5x`

Again divide both sides by `5` to isolate `x`, already defined as "the percent"

`22 = x`

Answer:

`"$55 is 22% of $250"`

`color(white)(..............)`―――――――

Check

Calculate `22%` of `250` to make sure it comes out to `55`

`color(white)(.....)250`
`color(white)(.)`×`color(white)(jj)` `.22` `larr` 0.22 = 22%
`color(white)(....)`―――
`color(white)(.....)` `500`
`color(white)(....)` `500`
`color(white)(....)`――
`color(white)(....)` `5500`

Count out the two decimal places

`55.00`

`Check`