Is `10^1000-1` divisible by both 9 and 11?

Can we conclude 10^(2n)-1 is divisible by both 9 and 11? Explain. Is 10^(2n+1)-1 is divisible by 11 or not? Explain.

A number divisible by both 8 and 11 is

Is 10^(2n)+1-1 is divisible by 11 or not. Explain.

Is 1221 divisible by 11 ?

Is 1221 divisible by 11 ?

Take any three digit number and write it two times to make a 6-digit number.Verify whether it is divisible by both 7 and 11.

Check whether 777 is divisible by both 3 and 9?

Check whether 786 is divisible by both 3 and 9 ?

Number divisible by 11 is