Question

How many times should the keys of a keyboard be pressed in order to type the first 300 counting numbers? (i.e. to type 1, 2, 3 ... 300)

Answer 1

for 1 to 9 :
9 times
for 10 to 99 :
2 × (99-10+1)
=2×90
=180 times
for 100 to 300 :
3 × (300-100+1)
=3×201
=603 times
total no.of times keys should be pressed
= 9 + 180 + 603
= 792 times

Answer 2

792 times should the keys of a keyboard be pressed in order to type the first 300 counting numbers.

Step-by-step explanation:

To find : How many times should the keys of a keyboard be pressed in order to type the first 300 counting numbers?

Solution :

The numbers are from 1, 2, 3 ... 300.

From 1 to 9,

The keyboard pressed 9 times.

From 10 to 99,

The keyboard pressed $2\times (99-10+1)$ times

The keyboard pressed 180 times.

From 100 to 300,

The keyboard pressed $3\times (300-100+1)$ times

The keyboard pressed 603 times.

Total number of times the keyboard pressed is

$n= 9 + 180 + 603$

$n= 792$

Therefore, 792 times should the keys of a keyboard be pressed in order to type the first 300 counting numbers.

#Learn more

https://brainly.in/question/9023931, Answered by Knjroopa