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Numerical Ability
Permutation and Combination
A printer numbers the pages of a book starting with 1 and uses 3189 digits in all. How many pages does the book have ?
A. 1000 B. 1074
C. 1075 D. 1080
Read Solution (Total 3)
-
- No.of digits in 1-digit page nos=1*9=9
" " 2-digit " =2*90=180
3-digit " =3*900=2700
" " 4-digit " =3189-(9+180+2700)=300
therefore no.of 4-digit page no's=300/4=75
total no.of pages=999+75=1074 - 12 years agoHelpfull: Yes(24) No(4)
- No.of digits in 1-digit page nos=1*9=9
" " 2-digit " =2*90=180
3-digit " =3*900=2700
" " 4-digit " =3189-(9+180+2700)=300
therefore no.of 4-digit page no's=300/4=75
total no.of pages=999+75=1074 - 13 years agoHelpfull: Yes(6) No(5)
- > 1 to 9 total 9 no.s each no have only 1 digit so 1*9 = 9 digits
> 10 to 99 total 90 no.s each no has 2 digits in it so 2 * 90 = 180 digits
> 100 to 999 total 900 no.s each no. has 3 digits in it so 3 * 900 = 2700 digits
> till now 9+ 180+ 2700 = 2889 digits are done
>book contains 3189 digits so remaining 300 digits are to be used
> each number from 1000 has four digits => 300 digits / 4 => 75 numbers
> 999+75 =1074 - 10 years agoHelpfull: Yes(3) No(1)
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