Agroup of students went to lunch. the bill before the sales tax and trip was $37.50 a sales tax of 8% was added. the group then tipped 18% on the amount after sales tax was added. what was the amount in dollars of the sale tax

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?