Answer: Melanie swam 63 minutes more in second week.
Explanation:
Given , Time taken by Melanie in first week to swim = 142 minutes
Combined time taken by her in first two weeks in swimming = 347 minutes
Now , time taken by her in second week = (Combined time of first two week) - (Time taken in first week)
= 347-142 minutes
= 205 minutes
Clearly , 205 > 142 i.e. She swam more in second week than first week./
Difference i= 205-142 = 63
Therefore, Melanie swam 63 minutes more in second week.