How many times the digit 9 occurs in the numbers between 100 to 999?

Explanation

Digit 9, occurs 20 times between 100 and 200. $\therefore$ No. of times digit 9 occurs between 100 to 899. = 20 $\times$ 8 = 160 times digits 9 occurs between 900 to 990 = (11$\times$9+2) Times = 101 Times digit 9 occurs between 991 to 999 = 9$\times$ 2 + 1 = 19 Times So the digit 9 occurs between 100 to 999 = 160 + 101 + 19 = 280 Times $\therefore$ So option (a) is the correct answer.