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

1 Answer
Tony B
Jun 4, 2016

#177.77bar7%# not accurate solution.

#177 7/9 %# accurate solution.

Explanation:

Method#-> ("difference")/("original value")xx100#

#=> (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=177.77bar7#

The #10x=1777.77bar7#

So #10x-x ->1777.77bar7#
#" "ul(" "177.77bar7)" "larr" subtract"#
#" "1600#

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

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