The number of digits of the smallest number, which when multiplied by 7 gives the result consisting entirely of nines is  Choose the correct answer
A) 3  B) 5  C) 6  D) 8  E) 9
Sol.   By hit and trial, we find that a number exactly divisible by 7 and consisting entirely of nines is 999999. Number of digits in it = 6.   Answer 6
<result>C</result>
The number of digits of the smallest number, which when multiplied by 7 gives the result consisting entirely of nines is