Question

Jon earned $38,000 last year. He paid $6,840 for entertainment. What percent of his earnings did Jon pay in entertainment expenses?

Answer 1

18%

Explanation:

Entertainment as a fraction of whole earnings is `6840/38000`

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`color(blue)("Shortcut method")`

`6840/38000 xx100 = 18%`

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`color(blue)("First Principle method")`
But what we need for this to be a percentage is to have `x/100`

To change `38000` into `100` we apply: `38000-:380 = 100`

So to change `6840/38000" into "x/100` we apply:

`(6840 -: 380)/(38000-:380) = 18/100 -> 18%`

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