Random Puzzles 

Workings

Hint
It's not just the vowels (AEIOU) that have a problem.

Answer
H, S, and T.

Reasoning
It should read:

"Can you tell what is wrong with this paragraph? At first glance you may think that just the vowels (AEIOU) have problems, but no! Three consonants also have problems, they have been replaced with the letter R, but which ones are they?"

Workings

Hint
Why does each column start with A, B, C?

Answer
Chicago.

Reasoning
Look at the letters at the bottom of each stack.

Workings

Hint
Try working backwards.

Answer
148.

148 x 6 = 888.

The easiest way is to divide successive 8's by 6 until you get an integer:
  8 ÷ 6 = 1.3333
 88 ÷ 6 = 14.666
888 ÷ 6 = 148

Workings

Hint
The answer involves multiplication (for example, 9 x 8 = 72).

Answer
468.

Reasoning
If we split each line in the following way:

98 68 88
72 48 64
14 32 24

Each new line is generated by multiplying the digits two at a time and writing the result below.

For example, 9 x 8 = 72, so 72 appears directly below 98.

And 7 x 2 = 14, so 14 appears directly below 72.

Double-Checking
9 x 8 = 72, 7 x 2 = 14, 1 x 4 = 4.

6 x 8 = 48, 4 x 8 = 32, 3 x 2 = 6.

8 x 8 = 64, 6 x 4 = 24, 2 x 4 = 8.