1
$\begingroup$

How many five-digit numbers divisible by 11 have the sum of their digits equal to 30?

I am able to get the 5-digit numbers divisible by 11

and

I am also able to get the five-digit numbers whose sum of their digits equal to 30.

But i am not able to get how i can get the count of 5 digit numbers satisying both the condition.

Thanks in advance.

Thanks in advance.

combinatorics permutations

  • 0
    Perhaps the following rule helps: A number is divisible by 11 if the sum the digits with alternating $\pm$ signs is zero or divisible by 112012-06-07
  • 0
    Rereading your questions it seems that perhaps it is not complete:You talk about 5 digit numbers, and 7 digit numbers.2012-06-07

2 Answers 2