How can you take 2 from 5 and leave 4?

What's the next in the series?

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

I can write cow in 13 letters.

Can You?

A large container is kept in open under the rain. Every passing hour, the water collected inside the container becomes double what it was.

In ten hours, the container is filled completely. Can you calculate how long would it have taken to be filled in half?

Can you find out what is missing?

1 3 5
2 4 ?

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

John, Jack and Jill are in a desert. John doesn't like Jill and hence decides to murder him. He poisons the water supply of Jill. Since it is a desert area, Jill must drink or he will die of thirst.

Jack does not know of the actions of John and also decides to murder Jill. To succeed in his ill motives, he removes the water supply of Jill so he dies of thirst.

Jill dies due to thirst. Who murdered Jill?

The ages of a father and son add up to 66.
The father's age is the son's age reversed.
How old could they be?
(3 possible solutions).

What does this rebus means ?

PROG WORKRESS

If,

20 % 5 = 24

21 % 7 = 33

42 % 6 = 67

Then;

66 % 6 = ?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?