If you write down all the numbers from 1 to 100, then how many times do you write 1 ? Choose one.
A) A)11  B) B)18  C) C)20  D) D)21  E) E)22
Explanation:   Explanation:   Clearly, from 1 to 100, there are ten numbers with 1 as the unit's digit- 1, 11, 21, 31, 41, 51, 61, 71, 81, 91; and ten numbers with 1 as the ten's digit - 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 100   So, required number = 10 + 11= 
<gadget id="calculator">10 + 11</gadget>
<output>21</output>
21.   Answer: 21
<result>D</result>
If you write down all the numbers from 1 to 100, then how many times do you write 1 ?