Becky was buying soup ingredients at the supermarket. She spent $6 on a pumpkin and also bought some sweet potatoes, which cost $0.50 per pound. In total, Becky spent $7.25 on the ingredients. How many pounds of sweet potatoes did she buy?

Becky spent a total of $7.25 on ingredients. Since she spent $6 on a pumpkin, we can find out how much she spent on sweet potatoes by subtracting the cost of the pumpkin from the total:

\[ 7.25 - 6 = 1.25 \]

So, she spent $1.25 on sweet potatoes. Since the sweet potatoes cost $0.50 per pound, we can find out how many pounds she bought by dividing the amount spent on sweet potatoes by the cost per pound:

\[ \frac{1.25}{0.50} = 2.5 \]

Thus, Becky bought 2.5 pounds of sweet potatoes.