When can we add 2 to 11 and get 1 as the correct answer?

What does this rebus means ?

Pronounced as 1 letter, And written with 3, 2 letters there are, and 2 only in me. I’m double, I’m single, I’m black blue and grey, I’m read from both ends, and the same either way. What am I?

The more it dries, the wetter it becomes. Can you tell what it is?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

Wednesday, Steve and Pam go to a restaurant to eat lunch. After eating lunch, they pay the bill. But Steve and Pam do not pay the bill. So…who does?

Can you discover the missing number in this series?

37, 10, 82
29, 11, 47
96, 15, 87
42, ?, 15

What kind of band never plays music?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

Replace the question mark with the correct number.