Hamsa and liam bake 108 oatmeal bars. hamsa makes 20 more bars than liam. find the ratio of the number of oatmeal bars hamsa bakes to the number of oatmeal bars liam number of oatmeal bars bars liam bakes

Your answer is 128:108. It doesn't say if they baked them together or not.

First, let x = number of oatmeal bars that Liam bakes

The expression should look like this:
(x + 20) + x = 108
Now, solve.
x + 20 + x = 108
2x + 20 = 108     Simplify the expression by making x + x = 2x.
     - 20      - 20   Subtract 20 to isolate x.

2x         = 88
---             ---   Divide them by two to isolate the variable x.
2               2

x           = 44    So, Liam baked 44 oatmeal bars.

Now, to find how many bars Hamsa baked, you have to do 44 + 20, because she baked 20 more than Liam. So, Hamsa baked 64 oatmeal cookies.

The ratio is now 64:44, which is 16:11 when simplified. 

Hope I helped!