問題詳情
2.Determine Ihe number of (staircase) paths in the xy plane from (2, 1) to (7，4), as shown in the following figure, where each such path is made up of individual steps going one unit to the right (R) or one unit upward (U). (20%)
參考答案
答案：B
難度：適中0.566667
統計：A(5),B(17),C(0),D(8),E(0)