To add 3/5 and 1/4, we need to find a common denominator. The least common multiple of 5 and 4 is 20.
So, we rewrite the fractions with the common denominator of 20:
3/5 = 12/20
1/4 = 5/20
Now, add the fractions together:
12/20 + 5/20 = 17/20
Therefore, 3/5 + 1/4 = 17/20 in simplest form.