GWD25-21

[CherrieLi]

21. Reid took 1 hour to cycle from his home to his college. The graph shows Reid's distance from his college during that hour. Reid's average speed for the last 15 minutes of the hour was how many kilometers per hour greater than his average speed for the first 45 minutes?

A.3
B.4
C.5
D.6
E.7

答案是C....Sorry, 我不會畫這個圖....且我的圖好像不太完整, 是否有人有完整的圖呢? 能否幫忙解題一下....感恩阿.....