Random Puzzles 

Workings

Hint
It's not just the vowels 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 have problems, but no! Three consonants also have problems, they have been replaced with the letter R, but which ones are they?"

Workings

Hint
Try working backwards.

Answer
Saturday.

Reasoning
It's best to work backwards:

   "Sunday's tomorrow"

is Monday.

   "the day after Sunday's tomorrow"

is therefore Tuesday.

   "five days before the day after Sunday's tomorrow"

is therefore Thursday.

   "yesterday was five days before the day after Sunday's tomorrow"

yesterday was Thursday, making today Friday. Therefore tomorrow is Saturday.

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.

Workings

Hint
Think about the first digits of the numbers.

Answer
There are more 2's because of the numbers beginning with 20,000.