Answer: Hence, there are 3.5y papers that he delivers in a week.
Explanation:
Let the number of papers delivers on Wednesday be 'y'.
Let the number of papers delivers on Sundays be

Let the number of papers delivers on Mondays be

Total number of papers he delivers in one week is given by
Number of papers on Wednesday + Number of papers on Sundays + Number of papers on Monday

Hence, there are 3.5y papers that he delivers in a week.