Why do we preferably have round manhole covers and not square ones?

Can you place three balls such that the equation shown in the picture holds true?

Three friends decide to distribute the soda cans they had among them. When all of them had drunk four cans each, the total number of cans that remained was equal to the cans each one of them had after they had divided the cans.

Can you calculate the total number of cans before distribution?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _

In the addition below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.
ABCABA
BBDCAA
ABEABB
ABDBAA
------- +
AAFGBDH
What does the complete addition look like in digits?

Why are televisions attracted to people?

I have branches, but no fruit, trunk or leaves. What am I?