Question

Find the ${28383}^{rd}$ digit: 123456789101112....

• A. 3
• B. 4
• C. 9
• D. 7

Answer 1

The correct option is A 3

There will be 9 single digit numbers using 9 digits, 90 two digit numbers using 180 digits, 900 three digit numbers using 2700 digits. Thus, when the number 999 would be written, a total of 2889 digits would have been used up. Thus, we would need to look for the ${25494}^{th}$ digit when we write all 4 digit numbers. Since, $\frac{25494}{4}=6373.5$ we can conclude that the first 6373 four digit numbers would be used up for writing the first 25492 digits. The second digit of the ${6374}^{th}$ four digit number would be the required answer. Since, the 6374th four digit number is 7373, the required digit is 3.