How many times in a given day, minutes and hour clock comes in a straight line ?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

Which digit occurred maximum times between the number 1 and 1000?

Can you find the ages of a son, father and grandfather based on the following facts?
The sum of the ages of grandfather, father and son is 140 years.
The age of the son in months is the same as the grandfather in years.
The age of the son in days is the same as the father in weeks.

Solve the equation in the image by looking at the pattern closely.

What Adam and Eve do not have but the rest of the people have?