Random Puzzles 

Workings

Hint
One of the words is GOAT.

Answer
slth   = sloth
rcn    = racoon
mnky   = monkey
llgtr  = alligator
lphnt  = elephant
lnd    = eland
gt     = goat (or agouti)
br     = bear (or boar)
bbn    = baboon
cyt    = coyote

Workings

Hint
Adding the speeds won't work.

Answer
205 mph.

Reasoning
If we take the number of miles in a lap to be L miles and use Time = Distance ÷ Speed.

The first ²/₅ are covered at 123 mph. Therefore, the time taken was [(²/₅) x L] ÷ 123 hours.

The next ²/₅ are covered at 164 mph. Therefore, the time taken was [(²/₅) x L] ÷ 164 hours.

The last ¹/₅ is covered at y mph. Therefore, the time taken was [(¹/₅) x L] ÷ y hours.

The entire trip is covered at an average of 150 mph, and we can conclude that:
 2L      2L      L     L
————— + ————— + ——— = ———
5x123   5x164    5y   150

Rearranging and simplifying gives:
 1     1    2     2
——— = —— - ——— - ———
 y    30   123   164

That means that y = 1 ÷ (¹/₃₀ - ²/₁₂₃ - ²/₁₆₄)

Using a calculator gives y = 205.

Workings

Hint
The answers have 4 letters.

Answer
When I pressed TARE on the scales, it brought a TEAR to my eye, as a piece of metal stuck in my finger. I didn't RATE this as a good experience.

Workings

Hint
There are lots of vowels.

Answer
A.

This is the vowels AEIOU intermingled with the reverse UOIEA.