How-many-times-does-the-digit-6-appear-when-writing-from-6-to-400-

Question Number 44038 by Tawa1 last updated on 20/Sep/18

How many times does the digit 6 appear when writing from 6 to 400 ?

Answered by $@ty@m last updated on 20/Sep/18

6, 16, 26, 36, 46, 56,

60, 61, 62, 63, 64, 65, 66, 67, 68, 69,

76, 86, 96

i . e . 20 t i m e s i n b e t w e e n 1 t o 100

\Rightarrow 80 t i m e s i n b e t w e e n 1 (o r 6) t o 400

Commented by Tawa1 last updated on 20/Sep/18

God bless you sir

Commented by $@ty@m last updated on 20/Sep/18

A n o t h e r w a y :

I n b e t w e e n 1 t o 100,

N o . o f n u m b e r s i n w h i c h u n i t

d i g i t i s 6 = 10

N o . o f n u m b e r s i n w h i c h t e n s

d i g i t i s 6 = 10

∴ 6 a p p e a r s 20 t i m e s i n b e t w e e n 1 t o 100 .

Commented by Tawa1 last updated on 20/Sep/18

God bless you sir

Answered by MrW3 last updated on 20/Sep/18

i n n u m b e r s w i t h o n e d i g i t :

1 t i m e

i n n u m b e r s w i t h t w o d i g i t s :

9 + 8 + 1 \times 2 = 19 t i m e s

i n n u m b e r s w i t h t h r e e d i g i t s :

3 \times (2 \times 9 + 1 \times 2) = 60 t i m e s

Σ = 1 + 19 + 60 = 80 t i m e s

Commented by malwaan last updated on 20/Sep/18

66; 166; 266; 366

1 O R 2 t i m e s ?

Commented by MrW3 last updated on 20/Sep/18

t w o t i m e s i n e a c h o f t h e s e n u m b e r s

Commented by Tawa1 last updated on 20/Sep/18

God bless you sir

Commented by malwaan last updated on 21/Sep/18

thank you sir

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