Tip is not factored twice. Each person paid $10 and each was given $1 back. So each person paid $9. $9 * 3 people = $27 + $2 (tip) = $29.
But it works out fine if the manager originally has the $30, gives back $3 and keeps $2 for the tip.
Quote:
Originally Posted by southlight
Like mentioned before it's more a trick than broken math. The story suggests your equation above, but that equation doesn't need to be solved. Another way to tell that this equation doesn't need to work is to split it up to its single values:
27 + 2 = 29
(25 + 2) + 2 = 29
In the last line you see that you factor the 2 $ tip in twice. Why would a equation containing the 2 $ tip twice need to make sense? It doesn't need to. Hope this helps.
Yep, another way to come to the same conclusion, just backwards calculated.
Best regards,
south
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