Answer:
1.) The total number of ski trials is 12.
2.)1.75
3.) 10.5
Explanation:
1.) There are 12 trails in total
2.) 3 1/2 - 1 3/4 == 1.75 OR 1 3/4
3.) 3.5+3.5+3.5 = 10.5 (there are 3 trails equal to 3 1/2)
x x x
x x x
x x x x x x
<-----I-------I------I------I-------I-------I--------I-------I--------->
1.75 2.25 2.5 3.25 3.5 3.75