Understand the problem
Source of the problem
Problem Solving Strategies Excursion In Mathematics
Start with hints
After having a long look into this problem you can first make attempt by listing the first few numbers of the given form.Give it a try!!!!!
So we can do it like this 8*(8)=64 8*(88)=704 8*(888)=7104 8*(8888)=71104 8*(88888)=711104 Now try to observe the pattern in the above table because here lies the main insight of this problem . Come on cook it up!!!!!!
So form the table you can observe the terms are following a pattern that’s is The first number is 7 Then k-2 number of 1 Then the last two digits are 04
Now try to make the sum to 1000
So now you are in the final part so you can easily find 7+04+(k-2)=1000
implies 11+(k-2)=1000 . Solving this equation we get the value of K is 991 which is the required answer.
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