30% of a number is 120. What is the number?

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Answer 1 · 2017-07-02T16:43:51

$400$

You divide $120/0.3=400$

You can double check by multiplying $400xx0.3=120$

Answer 2 · 2017-07-02T20:54:32

$n=400$

If we choose $n$ as the number, we can write an equation:

$30% " of " n = 120" "larr$ now solve for $n$

$30/100 xx n =120$

$n = 120 xx 100/30$

$n = 400$

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Or we can write equivalent fractions for the numbers and percentages as a direct proportion:

if $120$ is $30%$ , then what number will be $100%?$

$120/30 = x/100" "(larr"numbers")/(larr"percents")$

$30x = 120xx100" "larr$ cross multiply to get this

$x = (120xx100)/30$

$x =400$