1998 年

In the figure, $ABCD$ is a square of side $10\text{ cm}$. If $AE=AF$ and the area of $\triangle CEF$ is $20\text{ cm}^2$, which of the following equations can be used to find $AF$?

The figure shows the graph of $y=ax^2+bx+c$. Which of the following is true?

If $a$, $b$, $c$, $d$ are consecutive terms of an arithmetic sequence, which of the following must be true? I. $b-a=d-c$ II. $d$, $c$, $b$, $a$ are consecutive terms of an arithmetic sequence III. $a<b<c<d$

A man bought a box of $200$ apples for $\$500$. $10$ of the apples were rotten and the rest were sold at $\$4$ each. Find his percentage profit correct to 2 significant figures.

If $\dfrac{x+2y}{3x-4y}=5$, then $x:y=$

If $\dfrac{a}{b}=\dfrac{c}{d}$, which of the following must be true? I. $\dfrac{a}{c}=\dfrac{b}{d}$ II. $\dfrac{a+b}{b}=\dfrac{c+d}{d}$ III. $\dfrac{a-b}{b}=\dfrac{c-d}{d}$

If $x$ varies inversely as $y$ and directly as $z^2$, then

In the figure, $OAB$ is an equilateral triangle. Find the bearing of $B$ from $A$.

In the figure, the radii of the two circles are $3\text{ cm}$ and $1\text{ cm}$ respectively. Find the ratio of the area of the shaded part to that of the smaller circle.

The figure shows a right circular cone of base radius $4\text{ cm}$ and height $3\text{ cm}$. Find the area of its curved surface.