I make two people out of one. What 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 does this rebus mean?

O
N
C
E
TIME

Decode this picture on T-Shirt and tell what it says ?

A sundial has the fewest moving parts of any timepiece. Which has the most?

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

What do you call a fish without an eye?

What is the centre of gravity?