You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

Can you divide numbers from 1 to 9 (1 2 3 4 5 6 7 8 9) into two groups so that the sum of the numbers of each group is equal?

Note: 9 cannot be turned over to make it 6.

Below, you can see some coding:
January = 1017
February = 628
March = 1335
April = 145
May = 1353
June = 1064
July = 1074
August = 186

Now deciphering the way it has been coded, can you find out how September will be coded?

What is common among 11, 69, and 88?

Remove two matchsticks to make the below equation correct.

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

How many sides does a circle have?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?

I am sure no one can have two things for dinner. what are they?