Brain Teasers and Puzzles 

Workings

Hint
The answer involves months of the year.

Answer
6.

The number of letters each month has, starting with January, therefore August has 6 letters.

Workings

Hint
One inch = 25.4mm.

Answer
Millimetres in a mile.

Reasoning
One inch = 25.4mm.

So:

1 mile = 1760 yards = 1760 x 3 feet = 1760 x 3 x 12 inches = 1760 x 3 x 12 x 25.4 millimetres = 1,609,344mm in 1 mile.

And:

2 kilometres = 2000 metres = 2000 x 100 centimetre = 2000 x 100 x 10 millimetres = 2000 x 100 x 10 ÷ 25.4 inches = 2000 x 100 x 10 ÷ 25.4 x 16 = sixteenths of an inch ≈ 1,259,843 sixteenths of an inch in 2 kilometres.

Workings

Hint
There are 2.54cm in an inch.

Answer
250 centimetres.

Reasoning
One inch = 2.54cm.

And 1 foot = 12 inches = 30.48cm.

So, 8 feet = 243.84cm.

Workings

Hint
Think of chickens.

Answer
Don't count your chickens until they're hatched.