Subject: General Aptitude · Chapter: Number System · Exam: · Marks: · Difficulty:
How many zeros will be required to number the pages of a book containing 1000 pages?
(a)168
(b)184
(c)192
(d)216
Answer
Answer (as printed): C
Explanation
The pages of the book may be divided into 10 groups: (1-100), (101-200), (201-300),..........., (901-1000). Clearly, for the first group, one needs 11 zeros. For second to ninth groups, one needs 20 zeros each. For the tenth group, one needs 21 zeros. So, total number of zeros required $=11+8 \times 20+21=192$.
Explanation as extracted from the printed page; notation may be imperfect.