Answer:
total number of brown sugar cubes = 3
total number of white sugar cubes = 1
total number of sugar cubes = total no of brown sugar cubes + total no of white sugar cubes = 3 + 1 = 4
probability to select one brown sugar cube = total number of brown sugar cube / total number of sugar cube = 3/ 4
therefore the probability of selecting a brown sugar cube is 3/4 or 0.75