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toughies-units questions

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toughies-units questions

by raunekk » Mon Jun 16, 2008 4:35 am
1) n=?
1). The tens¡¯ digit of 11^n is 4
2). The hundreds¡¯ digit of 5^n is 6


what will be the answer guys????


2) What is the remainder when n is divided by 10?
1). The tens?digit of 11^n is 4
2). The hundreds?digit of 5^n is 6
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by anshul265 » Mon Jun 16, 2008 5:52 am
Answer for 1 is E.

Answer for 2 is A.

I haven't solved it through a proper mathematical way. I tried putting down values of few powers of 11 and 5 and spotted a trend. If you want I can try to explain that.
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thx

by raunekk » Mon Jun 16, 2008 8:01 am
of course i need d method:)...pls ..pls pls...
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by rakesheval » Sat Jun 21, 2008 8:04 am
answer to first should be E.
Explanation - when you calculate 11^2, 11^3..and so on..you will observe that 4 will appear at the tens place after every 10 such calculations..i.e. at 11^4, then at 11^14..and so on..similarly with 5, 6 appears at the hundredth place at every alternate power..i.e. at 4, 6, 8..
so both the statements are not sufficient to answer the question..

similarly the answer to second is A
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