First, let's figure out how long it takes him to eat one of his mother's pies. We do this by finding the number we multiply 1 1/2 to get 1, then we 45 minutes by the same number. We multiply 1 1/2 by 2/3 to get 1, so let's multiply 45 my 2/3rd. This is equal to 30 minutes. So, Paulo can eat one of his mother's pies in 30 minutes. From this information, it is clear that he can eat half a pie in 15 minutes.