Three fifths of cast have to sing. what fraction of cast doesnt

To solve this problem follow the steps below

Step 1: subtract 3/5 from the total of 5/5

5/5-3/5=2/5

Step 2(is optional):Check your answer

3/5 plus 2/5=5/5

Step 3: Write your answer

5/5=equals the total cast
2/5=the cast that doesn't sing
3/5=the cast that has to sing

2/5 of the cast doesn't have to sing

I hope this helps and I apologize in advance if any false information was given.

Two fifths, because if there was three fifths, the rest would be two fiths