I am an odd number. Take away a letter and I become even. What number am I?

You know three triplets: Frank John and Wayne (need to return your money). Frank always tells the truth while John and Wayne always lie. You meet one of them on the road and can ask him a three-word question.
Which question, will you ask?

What will you call your mother's brother's brother-in-law?

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

Count the number of squares in the picture below.

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

81 x 9 = 801. What must you do to make the this equation true?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

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?