perplexus.info :: Just Math : Lucky seven III

Lucky seven III (Posted on 2011-01-05)

N is a base ten positive integer formed by writing the digit 7 precisely 2010 times, that is N = 77....77 (2010 times).

Determine the digital root of [N/199].

Note: [x] denotes the greatest integer ≤ x.

*** For an extra challenge, solve this problem without using a computer program.

See The Solution Submitted by K Sengupta

Rating: 4.6667 (3 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

A lot of 7's

| Comment 3 of 6 |

There are a lot of 7's.

Posted by Math Man on 2011-01-05 15:28:21

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