What is the coolest letter in the alphabet?

A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

What word does this rebus represent?

meta meta
meta meta

It is a nine-letter word.
The exact opposite of the phrase "friendly and outgoing"
It contains the word "over".
It starts will a vowel.

What is it?

How many triangles are there in the picture below?

Speaking of rivers, a man calls his dog from the opposite side of the river. The dog crosses the river without getting wet, and without using a bridge or boat. How?

If a wheel has 54 spokes, how many spaces are there between the spokes?

What does an Island and the letter T have in common?

I am green and found in the forest and have needles instead of leaves. What am I?
Hint 1: It can be used for Christmas decorations.
Hint 2: I have a strong, scent that is used in air fresheners.