Answer:
20 homework problems were done on Monday and Tuesday together.
Explanation:
We have to use 12 and 8 to write a story.
A student does 12 homework problem on Monday. He does 8 homework problem on Tuesday.
Find total number of homework problem done by the student on Monday and Tuesday ?
Homework problem done on Monday = 12
Homework problem done on Tuesday = 8
Total homework problem done =

20 homework problems were done on Monday and Tuesday together.