If n is a 25-digit positive integer, all of whose digits are the same, which of the following must be true?
I. n is divisible by 5
II. n is divisible by 10
III. n is divisible by 25
Choose the correct choice.
A) I only B) I and II only C) I and III only D) II and III only E) I, II and III only
Rule for divisibility by 5: The sum of the digits of the number should be multiple of 3   Rule for divisibility by 10: The sum of the nos digits of the number should be divisible by 5 or the number should be divisible by 5 two times.   Rules for divisibility by 25: The sum of the digits should a multiple of 25   Consider no 11111111...25 times = The sum 25*1= 
<gadget id="calculator">25*1</gadget>
<output>25</output>
25----&gt; divisbible by 5,10 and 25   consider number to be 222....25 times, then sum of the no. 25*2=50 divisibly by 5,10 and 25   So why so because when you sum the numbers either you can add the digits 25 times or multiply the digit *25..   Note that since 25 is divisble by 25,10 and 5 and thus the sum of the nos will be divisible by all the nos.   Ans is I, II and III only
<result>E</result>
If n is a 25-digit positive integer, all of whose digits are the same, which of the following must be true?
I. n is divisible by 5
II. n is divisible by 10
III. n is divisible by 25