Count the number of 5-digit numbers (in the decimal system; integers from 1 to ) which are not divisible by 11.

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

, here a is first term, d is common difference and n is number of terms

So

n-1 = 8180

n= 8181

So total number which is not divisible by 11 = 90000-8181 = 81819

step-by-step explanation:

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341

step-by-step explanation:

all you have to do is 9x31 (which equals 279) and then 20x31 (which equals 620). then you have to subtract. 620-279=341.