the reason she can fill 1 and 1/4 tanks is because if you multiply 5 by 12 you get 60 and then you multiply 4 by 12 and its 48 so 48/60 is what you get meaning that it takes her 48 minutes to fill one tank and 48 plus 12 is 60 and 12 is 1/4 out of 48 so you get 1 and 1/4 tanks she can fill in one hour.
