Divisibility question MGMAT CAT

[fang6]

this is a question from MGMAT CAT - I have seen how this is resolved but the method offered by MGAT to resolve this does not seem that logic or straightforward to me and I want to see if someone else has another way to solve this

here is the question

10^25 - 560 is divisible by all of the following EXCEPT which one of the following :

11
8
5
4
3

thanks for your help

[shaji]

this is a question from MGMAT CAT - I have seen how this is resolved but the method offered by MGAT to resolve this does not seem that logic or straightforward to me and I want to see if someone else has another way to solve this

here is the question

10^25 - 560 is divisible by all of the following EXCEPT which one of the following :

11
8
5
4
3

thanks for your help

The fastest approach is to concentrate on the last three digits of the resulting number which is 440 preceeded by all 9's. The only number, from the ones shown above, that does not divide is 3.

[RonPurewal]

http://www.manhattangmat.com/forums/mga ... t2005.html

[fang6]

many thanks for help Ron, shaji - very helpful

[StaceyKoprince]

Excellent! And just want to remind everyone to take advantage of the search engine. We've had plenty of great discussions on lots of problems in the past, so if you search for your problem first, you may find you don't have to wait for an answer b/c your question has already been addressed in the past!

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