This is a math riddle often asked in Portugal to kids who are good at math. There are two versions of the same riddle, but if you can do one, you will most likely be able to do the other – I leave you both, just in case:

A hawk flies by a flock of doves and says:

Hello hundred doves.

We are not an hundred doves – the doves replied – but us, as much as us and a quarter  of us together, and you, hawk, makes an hundred.

So, how may are the doves in the flock?

In the second version, the doves reply, instead:

We are not an hundred doves, but us, as much as us, half of us and a quarter of us together with you, hawk, an hundred would be.

So, can you find out how many doves are in each of the flocks?