10. There is a cup filled with a $16 \%$ saltwater solution. There are large, medium, and small iron balls, with their volume ratios being $10: 4: 3$. First, the small ball is submerged in the saltwater cup, causing $10 \%$ of the saltwater to overflow, and then the small ball is removed; next, the medium ball is submerged in the saltwater cup and then removed; then the large ball is submerged in the saltwater cup and removed; finally, pure water is added to the cup until it is full. What is the concentration of the saltwater in the cup at this point? (Round to one decimal place)
Then, the "10 parts" volume of the large ball corresponds to $10 \% \div 3 \times 10=\frac{1}{3}$ of the saltwater, so the final amount of saltwater overflowed is $\frac{1}{3}$ of the cup's capacity. At this point, the concentration of saltwater in the cup is $16 \% \times\left(1-\frac{1}{3}\right) \div 1 \approx 10.7 \%$.