Random Puzzles 

Workings

Hints
The first letters of the words are: M, C, C, S, V, G, A, T, S, T, S, F, S, D, O.

Answers
---rix = matrix ---osy = choosy ---few = curfew ---oze = snooze ---uum = vacuum ---wth = growth ---nda = agenda ---nis = tennis ---tem = system ---pod = tripod ---reo = stereo ---hom = fathom ---gan = slogan ---amt = dreamt ---gen = oxygen

Workings

Hint
Look at the tops of the towers.

Answer
Add the two lines to the second tower from the left to complete the 'X' in the inverted letter sequence U, V, W, X, Y forming the towers' roofs.

Workings

Hint
How many 2 x 2 squares are there?

Answer
There are 93 squares without a rook.

Reasoning
There are 60 squares of size 1 x 1.
There are 33 squares of size 2 x 2.

Giving a total of 60 + 33 = 93 squares.

Workings

Hint
The answer is a whole number less than 10.

Answer
3.

Reasoning
We can multiply throughout by 12,
    X     X     X     X
    -  -  -  +  -  =  -
    X     2     4     12

to give:

   12 − 6X + 3X = X

        12 − 3X = X

             12 = 4X

              3 = X

As required.

Double-Checking
    3     3     3     3
    -  -  -  +  -  =  -
    3     2     4     12

    1 − 1.5 + 0.75 = 0.25

              0.25 = 0.25, which confirms that 3 is correct.