5 votes 5 votes How many n length base 10 numbers are there with at least 3 zeros? Combinatory shai-simonson combinatory + – Mk Utkarsh asked Jan 8, 2018 Mk Utkarsh 994 views answer comment Share Follow See all 25 Comments See all 25 25 Comments reply Show 22 previous comments Mk Utkarsh commented Jan 9, 2018 reply Follow Share Rishabh Gupta 2 number of 1 digit 10 base numbers are 10 :P(pretty obvious) 101 = 10 and 9 * 100 is 9 0 votes 0 votes Rishabh Gupta 2 commented Jan 9, 2018 reply Follow Share @Utkarsh What about 2 digit numbers? You can say that's 100. But this 100 includes 10 1-digit numbers(0 through 9) and 90 2-digit numbers(10 to 99). So, when you say n-digit number. $10^n$ will include 1-digit numbers, 2- digit numbers ...., n-digit numbers. In the question you fixed the digits to be n. 0 votes 0 votes Mk Utkarsh commented Jan 9, 2018 reply Follow Share So, when you say n-digit number. 10n will include 1-digit numbers, 2- digit numbers ...., n-digit numbers yeah correct but 10n also includes 2 digit base 10 number(with 0 as first digit) and other numbers till 99 that adds upto 100. 01 is a 2 digit base 10 number and a (single digit) whole number 0 votes 0 votes Please log in or register to add a comment.