Question

Rahul wanted to type the first 180 natural numbers find the number of time he had to press the numbered key


Plz help​

Answer 1

Answer:

432

Step-by-step explanation:

Number of times key was pressed for the numbers 1 to 9 = 9 Times

Number of times key was pressed for the numbers 10 to 99 = 90*2 = 180 Times (all are two digit numbers)

Number of times key was pressed for the numbers 100 to 180 = 81*3 = 243

Now add up all the numbers-

   9

+180

+243

= 432 Times