Seven parrots and some crows are perched on a tree branch. There was a noise and the same number of parrots and crows flew away. If only 2 parrots and 1 crow are left on the tree branch now, how many birds were perched on the branch to begin with? Let's be accurate as possible.
The number of parrots that flew away after the noise is 7 - 2 = 5. The same number of crows (5) flew away leaving 1 crow so there were 5 + 1 = 6 crows to begin with. The total number of crows and parrots was 7 + 6 = 13.
The answer: 13.