Is it too late to wish you a happy new year? It actually might be a bit early. Monday February 8 is the Lunar New Year and billions around the world are going to celebrate it. Ready for your New Year themed puzzle?
Every year, Sophie gets lucky money (or lì xì in Vietnamese) in beautifully decorated red envelopes from her relatives. It was quite the haul this year! She even discovered something interesting about the amount she received: she collected less than $100, and if she reversed the digits, she would have 20% more.
How much lucky money did she get?
Ready for the answer?
The best way to solve this puzzle is to get red envelopes and give a little lucky money to the kids in your life. OK, you may not be able to solve it that way, but you'll have a good time :)
While you could just solve this with trial and error, we here at Thai's Teaser Headquarters do not pass up the chance to solve it mathematically. Come save us, Algebra!
The problem can be written into an equation like this, where a is the 10s digit and b is the 1s digit.
10a + b + 1⁄5(10a + b) = 10b + a
12a + 6⁄5b = 10b + a
11a = 44⁄5b
5a = 4b
... which means that a = 4 and b = 5 (and 54 is 20% more than 45). And that means that Sophie has $45 to spend on more Star Wars merchandise.
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