Question

Question #47bec

Answer 1

`35.7%`

Explanation:

`0.25/70=0.357...`

`0.357xx100=35.7%`

Answer 2

`35 5/7%` Exactly

If you use decimals you do not have a precise answer

`~~35.71%` to 2 decimal places `larr` approximately

Explanation:

`color(blue)("Very important facts about percentages")`

Percent is just another fraction. The special thing about percent is that the bottom number (denominator) is fixed at 100.

The symbol % is like a unit of measurement but one where it is worth `1/100`

So as an example: 20%`->20xx%->20xx1/100=20/100`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(blue)("Answering the question")`

Let the unknown value be `x` then we have:

`25/70=x/100`

To 'get' `x` on its own we need to 'get rid' of the 100 in `x/100`. We do this by changing into 1 because `1xx x" gives just "x`

Multiply both sides by 100

`color(green)(25/70color(red)(xx100)" "=" "x/100color(red)(xx100))`

`color(green)(5/14color(red)(xx100) " "=" "x xx (color(red)(100))/100)`

but `100/100` is the same as 1 giving:

`x=35 5/7`

So we have:`" "(35 5/7)/100" "=" "35 5/7xx1/100" "=" "35 5/7%`