Can you replace the question mark with the correct number in the below table sequence?

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

Decode below rebus
D
N
A
T
S , D

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

Can you replace the X (both small and big x) with the numbers between 1 to 19 such that all the rows of 3 numbers between X (big x) sum to 23?

What am I?

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?

Why is 6 afraid of 7?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

How is a fly different from a mosquito?