Name the three-letter word that can complete the below words?

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E

What number comes next in the series?

5 15 5 18 5 24 14 20 _

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

Jenifer and Jesica are having a conversation.

Jenifer: I am definitely not over 30.
Jesica: I am 28 and you are surely 5 years older to me at least.
Jenifer: No, you are at least 29.

You are told that both of them are lying throughout in the conversation. Can you find their respective ages?

What is black when you buy it, red when you use it, and gray when you throw it away?

What kind of tree can you carry in your hand?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

Alpha is Beta's sister.

Gamma is a Beta mother.

Delta is Gamma's father.

Tango is Delta's mother.

Then,

How is Alpha related to Delta?