Question

when the integers from 1 to 1000 are written on paper the number of zeros used in writting is :
a)200
b)144
c)192
d)500​

Answer 1

$\rule{300}2$

Your Answer:

The correct answer is 192.

Explanation:

First, taking Zeroes between 1 to 99.

There are 9 numbers that include zeroes(i.e., 10,20,30,40,50,60,70,80,90)

So, According to Calculation.

From, 1 to 999 there must be

9×10= 90 zeroes

Now, the numbers that contain two zeroes (i.e., 100,200,300,400,500,600,700,800,900)

So, total 9×2

=18 zeroes

Now, the three digit numbers that contain zeroes between them.(101,102....109) total 9 zeroes in the line of one hundred, So, in line of two hundred there must be 9 zeroes also.

So, from 100 to 999

there are 9×9 = 81 zeroes

Now, In thousand there are three zeroes.

Adding All zeroes

= 90+18+81+3

= 192

$\rule{300}2$