A girl wrote all the numbers from 100 to 200. Then she started counting the number of one's that has been used while writing all these numbers. What is the number that she got?
From 100 to 200 there are 101 numbers.
There are 100, 1's in the hundred place.
10, 1's in tens place and10, 1's in unit place.
Thus, the answer is 100+10+10=100+10+10= 120.