Which four consecutive odds, when multiplied together, give the product 6xxxxxx9?
Each x represents a digit, not necessarily the same.
Checking 60000009^(1/4) and 69999999^(1/4) shows that they are about 88.01 and about 91.5
To have 4 odd numbers, the midpoint must be an even number, so probably 90. (if 88 was the midpoint, then our first 4th root calculation would have been slightly less than 88).
If the midpoint is 90, then:
87*89*91*93 = 65,529,009 Bob's your uncle.
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Posted by Larry
on 2024-06-21 09:57:01 |
solution
