Random Puzzles 

Workings

Hint
These are all Greek letters.

Answer
θ (theta).

Reasoning
These are all Greek letters, and they are:

   xi, chi, theta, psi, pi, phi

They all sound similar to each other, except θ.

Workings

Hint
You might need an old calculator.

Answer
Coil.

Reasoning
This is the only word that cannot be spelled using a calculator.

For example, if you enter 376616 into an old-fashioned calculator, and look at the number upside down, you can read GIGGLE.
376616  = giggle
7105    = soil
57738   = bells
378806  = gobble
4506    = gosh
5508    = boss
3704    = hole
5355378 = blesses
coil    = ????

Workings

Hint
Does ONE work, does TWO work? How many E's are there already?

Answer
Twelve.

"Cleverly, there are exactly twelve E's in this sentence."

Workings

Hint
How large would the smaller cube be?

Answer
1,352 small cubes.

Reasoning
The original large cube with 16 small cubes along each edge would require 16 x 16 x 16 = 4,096 small cubes.

Removing the outside layer would leave a large cube now with 14 small cubes along each edge (which requires 14 x 14 x 14 = 2,744 small cubes).

It isn't 15 small cubes because you're removing both ends of an edge.

Therefore, you have removed 4,096 − 2,744 = 1,352 small cubes.