Rachel saved money to buy art supplies. she used 1/3 of her savings to buy brushes. she used 3/5 of her savings to buy paint. what fraction of her savings does she have remaining?

This is a problem on addition of dissimilar fractions.
1/3 + 3/5 = ?
To add dissimilar fractions, we have to convert it first to similar fractions. To convert to similar fractions, find the Least Common Multiple (LCM) of the denominators. In this case, LCM is 15. Then rewrite the fractions using the LCM as the denominator.
1/3 = 5/15; 3/5 = 9/15
Now proceed with the addition -
5/15 + 9/15 = 14/15
Then subtract the sum from the savings -
1 - 14/15 = 1/15
Therefore, Rachel still has 1/15 of her savings