Brain Teasers and Puzzles 

Workings

Hint
The first letter can only be H, R, S, or E.

Answer
A hyena.

Reasoning
The 1^st letter can be: H R S E
The 2^nd letter can be: O Y T E
The 3^rd letter can be: E
The 4^th letter can be: P N D
The 5^th letter can be: B A

Workings

Hint
Do leap years make a difference?

Answer
Hours in 10 years.

Reasoning
In a day, there are 60 x 60 x 24 seconds = 86,400 seconds.

In 10 years, there are 10 x 365 x 24 hours = 87,600 hours, which even without the leap years is already the larger number.

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
The first letters of the words are: C, S, P, B. One of the vegetables is another word for rutabaga.

Answer
Carrot, swede, pea, bean.

Swede is another word for rutabaga.