In a room there are \(99\) right-handed persons and \(1\) left-handed person.
So the right-handed group makes out for \(99\%\) of the total.

How many right-handed persons must leave the room so that
this proportion lowers from \(99\%\) just to \(98\%\) of the total ?

The answer might surprise you because
an unexpected number of \(50\) right-handed persons have to leave the room !

In the room remain now \(99\) minus \(50\) or \(49\) right-handed persons.
And counted with the \(1\) left-handed person we arrive at \(50\) people in the room.
Thus we have the proportion \(49/50\), but that is \(98/100\) or \(98\%\) of the total.