Random Puzzles 

Workings

Hint
Don't forget the extra 9's in 90, 91, etc.

Answer
300.

Reasoning
Start with: 9, 19, 29, 39, 49, 59, 69, 79, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 – which is 20 9's.

We then repeat this for 100, 200, 300, up to 900 – which is 200 9's.

But from 900 to 999 we have an extra 100 9's as each starts with a 9.

So the total is 300.

Workings

Hint
Look at the letter positions in the alphabet.

Answer
R.

If you take the alphabetic positions of each letter in a row, the total is always 56.

Double-Checking
Y + G + W + A = 25 +  7 + 23 +  1 = 56
K + L + R + O = 11 + 12 + 18 + 15 = 56
Z + J + P + D = 26 + 10 + 16 +  4 = 56
V + F + T + H = 22 +  6 + 20 +  8 = 56

Workings

Hint
Try to rotate them around in your head, but watch out for mirror images.

Answer
B, E, and G.

Workings

Hint
Don't look at the first letters.

Answer
Duck.

The second letters of each word are the vowels in alphabetical order, fAwn, bEar, lIon, mOle, dUck.