Answer:
15
Explanation:
Since we're working with fractions, and the thirty ounce bucket is equivalent to 30/30. In order to make this easier, let's use the denominator of 30 for all of the fractions. Now that we've made them all equal, turning 1/10 to 3/30, and 2/5 to 12/30, let's add. 12 + 3 is 15, and 15/30 is half of 30/30. There was 15 ounces, or 1/2 of the tub, left.