Q. While purchasing one item costing Rs. 400, I had to pay the sales tax at 7% and on another costing Rs. 6400, the sales tax was 9%. What percent of the sales tax I had to pay, taking the two items together on an average?

1. 8%
2. 8(15/17)%
3. 8(13/17)%
4. 8(1/2)%