# What is the percent of increase from 270cm³ to 750cm³?

Jun 4, 2016

177.77bar7% not accurate solution.

177 7/9 % accurate solution.

#### Explanation:

Method$\to \left(\text{difference")/("original value}\right) \times 100$

=> (750-270)/270xx100 = 177.77bar7%

The bar over the last 7 means it goes on repeating for ever.
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
There is a trick you can use to deal with repeating decimals
You convert them to fractions. Sometimes you need to multiply by a different value: ${10}^{n}$ as appropriate

Let $x = 177.77 \overline{7}$

The $10 x = 1777.77 \overline{7}$

So $10 x - x \to 1777.77 \overline{7}$
$\text{ "ul(" "177.77bar7)" "larr" subtract}$
$\text{ } 1600$

So 9x=1600 => x= 1600/9 = 177 7/9 %