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| Subj:.....The
Price Of Eggs (S638)
From the book "More Mathematical Puzzles of Sam Loyd" Edited by Martin Gardner From: Dover Publications in 1960 |
Drawing from
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| "I paid
twelve cents for the eggs I bought from the grocer,"
explained the cook, "but I made him throw in two extra eggs because they were so little. That made the lot cost just one cent per dozen less than the first asking price." How many eggs did the cook buy? .
THE SOLUTION
The cook bought sixteen
eggs, but the grocer threw in
¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤»§«¤»¥«¤ My solution is the following: Let X = the original number of eggs The equation becomes Original price per dozen - One = New price per dozen Creating the equation from the word equation yields 12
12
144
144
X
X + 2
X
X + 2
Multiplying both sides of the equation by the common denominator of X ( X + 2 ) yields 144 ( X + 2 ) - 1 X ( X + 2 ) = 144 X Multiplying 144 X + 288 - X² + 2 X = 144 X Moving everything to the right side of the equation yields 0 = X² - 2 X - 288 Factoring 0 = ( X - 18 ) ( X + 16 ) Setting each factor equal to zero yields X = 16 or - 18 Therefore the answer is the cook bought sixteen eggs. |
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