Answer:
So total number which is not divisible by 11 = 89999-8181 = 81819
Step-by-step explanation:
We have to find the total numbers which are not divisible by 11 from 10000 to 99999
Total number from 10000 to 99999 = 99999-10000+1=90000
Just after 10000 the number which is divisible by 11 is 10010
And just below 99999 the number which is divisible by 11 is 99990
Using AP formula
[tex]T_N=a+(n-1)d[/tex], here a is first term, d is common difference and n is number of terms
So [tex]99990=10010+(n-1)11[/tex]
n-1 = 8180
n= 8181
So total number which is not divisible by 11 = 90000-8181 = 81819