Someone please help me ASAP

Ricardo ran the 400 meter race 3 times his fastest time was 54.3 seconds his slowest time was 56.1 seconds if his average time was 55.0 seconds what was his time for the third race

Ahiking trail is 6 miles long. it has 4 exercise stations, spaced evenly along the trail. what is the distance between each exercise station?

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.