How many keystrokes are needed to type numbers from 1 to 1000 on a standard keyboard? Select the correct option:  A) 2893  B) 3000  C) 5213  D) 5642  E) None of these
Explanation :   While typing numbers from 1 to 1000, we have 9 single digit numbers from 1 to 9. Each of them requires one keystroke. That is 9 key strokes.   There are 90 two-digit numbers, from 10 to 99. Each of these numbers requires 2 keystrokes. Therefore, one requires 180 keystrokes to type the 2 digit numbers.   There are 900 three-digit numbers, from 100 to 999. Each of these numbers requires 3 keystrokes. Therefore, one requires 2700 keystrokes to type these 3 digit numbers.   And,1000 is a four-digit number which requires 4 keystrokes.   Hence, total  9+180+2700+4= 
<gadget id="calculator"> 9+180+2700+4</gadget>
<output>2_893</output>
2893 keystrokes is required.   2893nswer : 2893
<result>A</result>
How many keystrokes are needed to type numbers from 1 to 1000 on a standard keyboard?