Help me to do this question too​

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?

Find the difference in area between the circle and the triangle. click on the answer until the correct answer is showing. possible answers: a = 4 pi - 8a = 9 pi - 9/2 √3a = 16/3 pia = 16a = 27 pi

Round the number to the hundredths place. 26,379.87492 a. 26,379.87 b. 26,379.88 c. 26,380 d. 26,400