F.1 Maths題(english)

方法1：
Let x be the number of residents last year.
(1-15%)x = 221
85% x = 221
x = 221/85%
x = 260
∴There were 260 residents laxt year.

方法2：
The number of resident last year
=221/(1-15%)
=221/85%
=260

Let a be residents were there in the village last year.

a x(1-15%)=221
a=221÷８５％
　　　　ａ＝２２１x１００／８５
　　　　ａ＝２６０

∴ｔｈｅｒｅ　ｗｅｒｅ２６０residents　in the village last year．