Random Puzzles 

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
Look at the number of letters in each name.

Answer
Yes.

Because there is an odd number of letters in the name.

Workings

Hint
Does it start with January?

Answer
28.

The number of days in each month starting from October. The answer could also be 29 for a leap year.

The answer can't be 30, as the question specifically says that the answer is not 30, so it can't be the sequence starting with May.

Workings

Answer
293 031: these are the numbers 20, 21, 22, 23 etc grouped into three digits.