Please help me with this

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?

The stem-and-leaf plot shows the heights in centimeters of teddy bear sunflowers grown in two different types of soil. soil a soil b 5 9 5 2 1 1 6 3 9 5 1 0 7 0 2 3 6 7 8 2 1 8 3 0 9 key: 9|6 means 69 key: 5|8 means 58 calculate the mean of each data set. calculate the mean absolute deviation (mad) of each data set. which set is more variable? how do you know?

Amotorboat maintained a constant speed of 12 miles per hour relative to the water in going 45 miles upstream and then returning. the total time for the trip was 8.0 hours. use this information to find the speed of the current.