find all the integer which are equal to 11 time the sum of sum of their digits

 hmm.

(1) We need not consider negative numbers since the sum of their digits is positive.

(2) 0 works since 0=11*0

(3) We need only check further multiples of 11. We find that 198 works since 11(1+9+8)=11(18)=198.

No other integer works. The greatest possible sum of digits for a three digit number is 27, and 11*27=297. The greates possible sum of a four digit number is 36 and 11*36=396. Thus the numbers are always larger than 11*(sum of digits) for all numbers greater than 199.

The solution is 0 and 198.

no copyright intended... :P

  • 5

@suspense; correctly answered the question. Very good! Keep it up. Thumbs up for you.

 

Cheers!!

  • -2

thnxx..!!!

  • -1
What are you looking for?