Answer:
3/4
Explanation:
so if it takes the master baker 6 minutes and they work on the cake for one minute that is 1/6 if it takes the student 12 minutes that is 1/12. so you do
1/12 x 1/6 and you find the LCD so that is 1x2/6x2 which makes 2/12 + 1/12 = 3/12 and you simplify by dividing the top and bottom by 3 which is 1/4 so if they decorated 1/4 of the cake that leaves 3/4 of the cake left.