Respuesta :

pegah
you should know that 3 1/4 is equal to 13/4 so she should use 13 cups of 1/4 cups :)))) 
and for finding that you should say: 
if I have 3 and 1/4 so is equal to ((3*4)+1)/4= 13/4 :)))
I hope this is helpful 
have a nice day