Random Puzzles 

Workings

Hint
Circumference = 2 x Radius x π.

Answer
6.28 metres, a lot less than you might think!

If we call the radius of the Earth R, then the difference between the two circumferences is:

2 x π x (R + 1) − 2 x π x R
   = 2 x π metres
      = 6.28 metres.

Workings

Hint
Think about the alphabet.

Answer
No.

Only people with initials A-M do like chocolate, others do not.

Workings

Hints
All of the words are three letters long.

Answers
First set:
bot = small robot bit = small part but = on the contrary bat = nocturnal mammal bet = wager
Second set:
hit = struck het = heated (archaic British) hut = straw dwelling hat = a head warmer hot = not cold

Workings

Hint
helium = h-- + l--

Answers
helium = hum + lie latest = let + sat almond = man + old eldest = led + set placed = cap + led radium = air + mud desert = red + set wealth = law + the tricky = cry + kit funnel = elf + nun
Alternative Answers
The following answers use less common words.

helium = him + leu
helium = hue + mil
helium = hum + lei

latest = els + tat

almond = don + lam
almond = lam + nod

eldest = eld + set
eldest = els + ted

placed = pec + lad

radium = mud + ria
radium = amu + rid
radium = aid + rum

wealth = awl + the
wealth = haw + let

There are more answers with even rarer words, but I've chosen not to include those.