If seeds are 8 per pound then you need to find the unit rate and make a proportion with how much she spent. So you can make a ratio of 1(pound) / $8 compared to x(pounds) / $10. Then, cross-multiply.
10 = 8x. Divide both sides by 8
10/ 8 = x Simplify the fraction
1 1/4 = x
So, she bought 1 1/4 pounds of seeds