由於題目最後問AB兩市距離,所以我設
﹒ ﹒ ﹒ Distance between AB = x km
另尾二句指Gary遇到Connie後0.5hr再遇到Louisa,所以我用
﹒ ﹒ ﹒ Time lag between GL and GC = 0.5
列式。將左邊的英文換成符號就列到式,例如
﹒ ﹒ ﹒ (Time taken for G and L to meet) - (Time taken for G and C to meet) = 0.5
﹒ ﹒ ﹒ x/(60 + 80) - x/(65 + 80) = 0.5
﹒ ﹒ ﹒ x(1/140 - 1/145) = 0.5
﹒ ﹒ ﹒ x = 2030
再作答
﹒ ﹒ ﹒ Hence the distance between A and B is 2030 km §