Understanding a riddle: How many flowers in a bouquet, if all but two are roses, all but two are tulips, and all but two are daisies? This is quite a popular riddle in interviews and in general: > In a bouquet of flowers, all but two are roses, all but two are tulips, and all but two are daisies. How many flowers are in the bouquet? The answer is $3$. My question is how exactly this is $3$? I suspect that answer lies in correct understanding of " **all but two are** ". Please help me to understand the answer.

Let $n$ be the total number of flowers. When the problem says that all but two of the flowers are of one kind, it means there are $n-2$ flowers of that kind. Therefore, $n-2$ of them are roses, $n-2$ of them are tulips and $n-2$ of them are daisies. Assuming that this exhausts the list of flowers, we can write $n-2+n-2+n-2 = n$ which gives $n=3$