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 p99410 January 14th, 2014 02:45 PM

A question that sounds like a middle school one

Among the one hundred numbers 1^2, 2^2, 3^2, ..., 99^2, 100^2, how many of them have an odd number as the tens digit?

The answer sheet says to try, but I don't like that :wink:

 Slinkey January 14th, 2014 03:11 PM

Re: A question that sounds like a middle school one

Quote:
 Originally Posted by p99410 Among the one hundred numbers 1^2, 2^2, 3^2, ..., 99^2, 100^2, how many of them have an odd number as the tens digit? The answer sheet says to try, but I don't like that :wink:
I'm going to stick my neck out and say 20.

The pattern seems to be, if the number ends in 4 or 6 then it will be odd, otherwise it is even, except for squares of 1, 2, and 3 whose squares are less than 10.

 p99410 January 18th, 2014 03:18 PM

Re: A question that sounds like a middle school one

Thanks, problem solved.

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