Question Number 53902 by mr W last updated on 27/Jan/19

Commented by tanmay.chaudhury50@gmail.com last updated on 27/Jan/19

Commented by Tawa1 last updated on 27/Jan/19

Commented by mr W last updated on 27/Jan/19

Answered by tanmay.chaudhury50@gmail.com last updated on 27/Jan/19
![calculation of zdroes... 1)one digit no →use of zero→is 0→0■ 2)Two digit no→when unit place →0 tength digit can be filled by any number→(1,2,3..9) so 9 numbers →9■ 3)Three digit number→unit place→0 tength place can be filled →(1,2,...9)→9ways hundred can be filled →(1,2...8)9 ways so total=1×9×9=81 now use of 0 in this 81 numbers=81■ Three digit no unit place→0 [also tenth place →0 hundred place →can be filled →using( 1,2,3..9) →9 ways →9 numbdrs →e.g[100,200,..900] use of 0 in this 9 numbers=9×2=18■ Three digit no tength place 0→unit plac(1 to9)→ hundred place →any number (1,2,3..9) 9×1×9=81 use of 0→1×81=81■ 4)four dugit no −^× −^× −^× −^0 →9×9×9×1=729 −^× −^× −^0 −^× →9×9×1×9=729 −^× −^0 −^× −^× →9×1×9×9=729 −^× −^× −^0 −^0 →9×9×1×1=81 −^× −^0 −^× −^0 →9×1×9×1=81 −^× −^0 −^0 −^× →9×1×1×9=81 use of 0 [729+729+729]×1■ use of 00[81+81+81]×2■ −^× −^0 −^0 −^0 →9×1×1×1=9 use of 000=9×3=27■ sir pls check till now to get the use of 0 we have to add ■ marked value... pls check.. i have cslculated only use of 0 till now..](https://www.tinkutara.com/question/Q54003.png)
Commented by mr W last updated on 27/Jan/19

Commented by Otchere Abdullai last updated on 27/Jan/19

Commented by tanmay.chaudhury50@gmail.com last updated on 28/Jan/19

Commented by Tawa1 last updated on 28/Jan/19
