Brain Teasers and Puzzles 

Workings

Hint
Think of the phrase 'my bucket and spade'.

Answer
In the phrase 'my bucket and your spade', the gap between 'my' and 'and' is the same as the gap between 'and' and 'spade', namely one word.

Indeed, this logic can be continued to give the following sentence. In the first sentence the gap between 'and and' and 'and and' is seven words, et cetera.

Workings

Hint
Say each number, one digit at a time.

Answer
11131221141113122112.

Reasoning
Each term describes the previous term.

For example, 42 = one four, one two = 1412.

And, 1412 = one one, one four, one one, one two = 11141112.

Workings

Hint
There are 16 ounces in a pound, and 144 in a gross.

Answer
Seconds in an hour.

Reasoning
There are 16 x 144 = 2,304 ounces in gross pounds.

There are 60 x 60 = 3,600 seconds in an hour.

Workings

Hint
A little bit of algebra might help.

Answer
I have 14 apples and you have 28 apples.

Reasoning
We can work this out with a little algebra. I have A apples and you have B apples, then
[1]  5 x (A – 7) = B + 7

[2]        A + 7 = B – 7

From [1] we have:

    5A – 35 = B + 7
[3]      5A = B + 42

From [2] we have:

[4]  A + 14 = B

We can then use [4] in [3] to give:

  5A = (A + 14) + 42
  5A = A + 56
  4A = 56
   A = 14

Which gives B = 28 (by [4]).