Fraction. please show work

Question

Tom wrote in ajournal over the summer. If he wrote in 3/5 of the pages, what fraction of pages were still blank at the end of the summer

Answer 1

5/5 - 3/5 = 2/5 were still blank

or

1 - 3/5 = 2/5, and 1=5/5, so

1-3/5 = 5/5-3/5 = 2/5