This is something of a random thought I had while working on another puzzle entirely... it is quite easy IF you see the solution immediately, so certainly one for the newer members of this site to have a go at (if the highly skilled puzzlers here wait a day or two to give others a chance, of course...)
Riddle of the colours
If two Purples make a Blue
And two Blues make a Red
And two Yellows make a Green
How many Reds make a Yellow?
There is enough information here to solve the puzzle, if you know where to look...
mathandcalculationtags misleading? $\endgroup$