279
To count the total digits used in numbering 129 pages, we split the page numbers into groups based on the number of digits.
Pages 1 to 9 (1-digit numbers): There are 9 pages, each using 1 digit.
Digits used = \(9 \times 1 = 9\)
Pages 10 to 99 (2-digit numbers): There are \(99 - 10 + 1 = 90\) pages, each using 2 digits.
Digits used = \(90 \times 2 = 180\)
Pages 100 to 129 (3-digit numbers): There are \(129 - 100 + 1 = 30\) pages, each using 3 digits.
Digits used = \(30 \times 3 = 90\)
Total digits = \(9 + 180 + 90 = 279\)
Hence, the correct answer is 279.
Important Questions from Number System
What is the value of 1 2 + 2 2 + 3 2 + ......21 2 ?
Find the greatest number which divides 36, 64 and 92 in such a way that in each case same remainder is left.
Which sequence is correct to represent the hierarchical chain of number system?
(Where N - Natural Numbers
W - Whole Numbers
Q - Rational Numbers
Z - Integers)
The difference of the place value and the face value of 5 in 26549 is :
What must be added to 45680 to make it exactly divisible by 9?
