Bus Driver’s Age

Imagine you are driving a bus. On the first stop 3 people get in the bus, on the second one 5 more get in, on the third stop 2 get out and 4 get in, on the last stop everybody gets out. How old is the bus driver?

You are imagining the story, so the bus driver is as old as you.

The Fragile Bridge

You have to cross a long bridge which supports weight up to 180 pounds. However, you weigh 175 pounds and also carry with yourself 3 golden eggs, each of which weighs 2 pounds. How can you get to the other side?

 P. S. If you leave an egg unattended, someone can steal it.

Simply juggle the eggs while crossing the bridge.

Haystacks

You have 10 fields and keep 1 haystack in the first one, 2 haystacks in the second one, 3 haystacks in the third one and so on. How many haystacks will you have if you combine all of them in your first field?

You will have one big haystack.