The number of times the digit 3 will be written when listing the integers from 1 to 1000 is

Any number between 1 to 999 is a 3,digit number xyz where the digits xyz are any digits from 0 to 9.are any digits from 0 to 9.Now, we first count the numbers in which 3 occurs onceonly- Since, 3 can occur at one place in  3C1, ways, thereare 3C1⋅(9×9)=3⋅92 such numbers3C192+2×3C2×9+3×3c3=243+54+3=300