[問題]考古題Form21 sec7 PS-Q20

[凱薩琳]

A square board the has an area of 25 squares inchs is to be cut into pieces, each of which is a square with sides of length 1,2, or 3 anches. What is the least number of such square pieces into which the boars can be cut?

(A)5
(B)6
(C)7
(D)8
(E)9

Ans:D

[Ace]

求最小數的平方塊
要讓邊長3in最多才可....ˇin的面積為9
雖然兩論上可以放兩塊9in,但是因為原board邊長只有5
所以無論如何只能放一個
只要把邊長3in的放在四個角其中一
再配合邊長2和1的平方塊
即可知25in的board可以由一個3in,三個2in,4個1in組成

[scujean]

畫出圖 就很好解了..