What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

How can you make number one disappear by adding something to it?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

Which word does the below Plexor means ?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

I’m tall when I’m young, and I’m short when I’m old. What am I?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

In the picture, you can see a chess board. On the top left position, the K marks a knight. Now, can you move the knight in a manner that after 63 moves, the knight has been placed at all the squares exactly once excluding the starting square?

Every words stands for unique digit that makes the arithmetic equation true

SEVEN + SEVEN + SIX = TWENTY.

What are the digits ?