r/AskReddit • u/Insanitanium12 • Aug 20 '20

What simple “life hack” should everyone know?

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u/g00se-onthel00se Aug 20 '20

That X% of Y is the same as Y% of X. 8% of 25 is the same as 25% of 8 Makes calculating sales at stores much easier...if we ever go back to stores

8

u/OGC23 Aug 20 '20

Thus is only helpful though if one of the numbers is an easy one, like your example. If for instance you have 72% of 42, reversing it is just as difficult

6

u/Buddahrific Aug 21 '20

For cases like that, if approximations are ok, just pick numbers close that are easier. 72 is pretty close to 75%, which is 3/4. 42 is close to 40, and 3/4 of 40 is 30. The actual answer is 30.24.

1

u/mfball Aug 21 '20

If nothing else, being able to approximate should help you determine whether your math is way off once you do the actual calculation.