Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

Considering the below equation:

V + II - VI = 10
IV - X + VIII = 20
IV - VII + VI = 30

Then, I + II + III = ?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

You bought me for dinner but never eat me. What am I?

How can you take 2 from 5 and leave 4?

You need to remove two matchsticks to make the below equation true. Can you do it ?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

In a boat, the father of a sailor's son is sitting with the son of the sailor. However, the sailor is not present on the boat.

Can this even be possible?

The below mentioned letters have been placed in a order using a logic.

DEAD, BALL, FEAR, SHOP

Can you find the logic?

What building has the most stories?