Question

How many times would digit 2 be written, if you wrote down all the whole numbers from 1 to 100?

Answer 1

2 In one's place
2, 12, 22, 32, ........., 92
$\to 10times$
2 In ten's place
20, 21, 22, ........., 29
$\to 10\times$
$\therefore$ Total number of times digit 2 is written = 10 + 10 = 20 times