What is greater than gold but cannot be bought. it can never be sold and can earn if its sought. though it can be broken, it can still be fixed. for by birth it can't start nor by death it is ended.what am i?

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

Can you replace the question mark with the correct number?

Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

You can see three almost identical images below. Can you spot the odd one out from them?

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

I am beautiful, up in the sky. I am magical, yet I cannot fly. To people I bring luck, and to some people, riches. The boy at my end does whatever he wishes. What am I?