maths ce 2000 mc q12,16,42

2000 Q12

Area of triangle BCD = (1/2) (1) (4) = 2 cm^2
Divide the triangle BCD as shown in question
Area of the smaller triangle (without shaded area) : Triangle BCD = (3)^2 : (4)^2 = 9:16
So, area of smaller triangle = 9 / (16/2) = 1.125 cm^2
Area of shaded area = 2 - 1.125 = 7/8 (Answer B)

2000 Q16
Option I
Becuz 3^3 / 3 = 9
Becuz 3^5 / 3^3 = 9
Option I has common ratio
So it is a geometric sequence

Option II
Becuz 999 / 9 is not equal to 999 / 99
So no common ratio
So is not a geometric sequence

Option III
Becuz -100 / 10 = 1000 / -100 = -10
Option III has common ratio
So it is a geometric sequence

Answer C

2000 Q 42
Consider x >= y
If x>= y
Region must be either II, III, or IV

Consider 0 <= y <=3, together with x > y
Only Possible answer is II or III
So answer D

2014-03-03 23:13:32 補充：
2000 Q 42
好難寫 Step
考試見到 E D 題目就 sub 數計
最快

sorry ,not Q42 , is Q39 !