  Math Central - mathcentral.uregina.ca  Quandaries & Queries    Q & Q    Topic: sum of the digits   start over

5 items are filed under this topic.    Page1/1            How many numbers from the set have the sum of its digits equal to 2? 2019-10-24 From Marcel:Hello. My question is the following: Given the set {1,2...........10exp2019}, how many numbers from the set have the sum of its digits equal to 2? I got some of them : 2 20 200 2000 20000 .......2. 10exp2018 11 110 1100 11000 110000....101 1010 10100 101000 1010000....10011 10010 100100 1001000 1010000.....10001 100010 1000100 10001000,,,,,,100001 1000010 10000100....... My problem is that I have difficulty in finding a strategy to obtain the exact quantity of numbers. Please help me, thanksAnswered by Penny Nom.     The sum of the digits of two-digit number is 9 2008-07-01 From Audrey:the sum of the digits of two-digit number is 9. if the digits are reversed, the new number if 63 greater than the original number. find the number.Answered by Penny Nom.     111...111 * 2003 2008-06-23 From Peggy:Number a = 111...111 formed by 2003 1's. Find the sum of the digits of the number 2003 * a.Answered by Penny Nom.     The sum of the digits of a number 2008-06-23 From Ben:Question: Using mathematical induction, prove that if the sum of the digits of a number is divisible by three, then the number itself is also divisible by 3.Answered by Penny Nom.     The sum of the digits of 2^100 2005-06-11 From Richard:The sum of the digits was calculated for the number 2100, then the sum of the digits was calculated for the resulting number and so on, until a single digit is left.Answered by Penny Nom.      Page1/1    Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.    about math central :: site map :: links :: notre site français