It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

No matter how little or how much you use me, you change me every month. What am I?

Our product and our sum always give the same answer. Who are we?

What has many keys but can’t open a single lock?

I taste better than I can smell. Who am I?

Replace the (?) with the correct mathematical signs to make the expression equal to 59.

18 ? 12 ? 4 ? 5 = 59

Arrange the numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 above and below the division line in a manner that the thus formed fractions equal to 1/3.

(You can use one number only once)