what's the probability of getting a king or a queen from a pack of 52 cards?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

I have feet, but no legs. Which animal Am I?

Cristina leaves home and then she makes exactly 3 left turns and returns home where she found 2 girls wearing the mask.

Who are these two masked girls?

Find The Missing Number In the Sequence.
6 25 64 ? 32 1

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

Rob is taller than Edwin, and Jurgen is shorter than Rob.
Of only one of the following statements, we now certainly know it is correct:

A.Edwin is taller than Jurgen
B.Jurgen is taller than Edwin
C.It cannot be determined if Jurgen or Edwin is the tallest.

Find the next number in the series below

21 32 54 87 131 ?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?