Random Puzzles 

Workings

Hint
Try: pale + tone, veil + june, peer + date.

Answers
pale + tone = antelope
veil + june = juvenile
peer + date = repeated, departee
snob + wall = snowball
time + seat = estimate, meatiest, teatimes

Workings

Hint
Look at the last letters.

Answer
Steve.

The last letters are in alphabetical order.

Workings

Hint
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
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.