counting and probability help

107, 109, 117, 119, 127, 129, 137, 139, 147, 149, 157, 159, 167, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 187, 189, 190, 191, 192, 192, 193, 194, 195, 196, 197, 198, 199 (37) 

207, ... , 299 (37)

...

700, ... , 799 (100)

...

900, ... , 999 (100) 

37 * 7 = 259

259 + 100 + 100 = 459

777 and 999 (- 2) and 171/191, 272/292, 373/393, 474/494, 575/595, 676/696, 797, 878/898, 979 (- 16)

(- 16) - (- 2) = (- 18)

459 - 18 = 441

So there are (457 - 18 =) 441  numbers that at least have one 7 or one 9 as digits.

Correct me if I am wrong. (probably wrong)

ignore my message, i'll do it again

Thanks anyway:

I got 452 :)

Can you show us how..?

I understand my mistake now 179, 197,,,