Question

How many natural numbers less than 10^8 are there,whose sum of digits equals to 7?

Answer 1

Hello dear @user your answer....



the numbers have 8 place(some of which might be zero),And there are 7 units of value to go into them.(which place can have at most 9units,but that is automatic since their is only 7 units total.)so it's a star and bars problem which 7 star and 7 bar,making (14/7)=3432watch numbers..


(edited 8 not 7)....

${hope it helps you and thank you$

Answer 2

the numbers have 8 place(some of which might be zero),And there are 7 units of value to go into them.(which place can have at most 9units,but that is automatic since their is only 7 units total.)so it's a star and bars problem which 7 star and 7 bar,making (14/7)=3432watch numbers..