Answer:
Given the equivocal nature of this question, I will need to draw an assumption: I will assume that Ali ate from the cake and so did Jason — not Ali ate from the cake and Jason ate from Ali’s slice.
With that being said, the first approach is make both of these fractions have a common denominator, so that we can find how much each respective person ate from the total amount of slices. Intuitively, the common denominator is 12
12
, so this must be true:
Ali ate 4/12
4
/
12
of the cake;
Jason ate 3/12
3
/
12
of the cake
Adding these two fractions will give us 7/12
7
/
12
— the total amount eaten. Now, to find the amount left, we need only subtract 7/12
7
/
12
from 12/12
12
/
12
(the total amount of the cake). Doing so will give us
Explanation: