Answer:
152 miles
Explanation:
There are 2 Xs above 20 1/2, so she rode that distance twice. There are 3 Xs above 22 1/2, so she rode that distance three times. The other distances with Xs she only did once. We add up the distances for each X to get the total:
20.5 + 20.5 + 21.5 + 22 + 22.5 + 22.5 + 22.5 = 152 miles