天天天藍 发表于 23-7-2014 08:45 AM
常常听说新加坡的水准高。。
但我遇过不只一个新加坡同事会问我类似以下的问题。。。
大家出来社会工作也是为了找几个钱。。。苟且过一天也就一天。。。。不过PSLE就真的不是开玩笑的。。
像这样的数学section B 每年都会有。。。。。。小六真的是有够凄惨的。。。
Example 4
The square is divided into four parts A, B, C and D as shown. The ratio of Area A to Area B is 4 : 3. The ratio of Area B to Area C is 2 : 1.
a) Find the ratio of Area A to Area B to Area C.
b) Area D is 220 cm2. Find the area of the square.
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Keynote
a) Write equivalent ratios such that common ratio units, i.e. Area B is the same, then combine the ratios
b) Area D = different in ratio units between (A+B) and C
Solution
a)
A : B = 4x2 : 3x2 = 8 : 6
B : C = 2x3 : 1x3 = 6 : 3
A : B : C = 8 : 6 : 3