1987 年

$ABCD$ is a trapezium in which $AB\parallel DC$, $AB=8\text{ cm}$, $DC=18\text{ cm}$, $AD=BC=13\text{ cm}$. Find the area of the trapezium.

A solid rectangular iron block, $4\text{ cm}\times2\text{ cm}\times1\text{ cm}$, is melted and recast into a cube. The decrease in the total surface area is

Figure a shows a circular measuring cylinder $4\text{ cm}$ in diameter containing water. Three iron balls, each of diameter $2\text{ cm}$, are dropped into the cylinder as shown in Figure b. What is the rise in the water level?

Find, correct to the nearest dollar, the compound interest on $\$10\,000$ at $8\%$ p.a. for 4 years, compounded half-yearly.

If the selling price of 5 pens is the same as the cost price of 6 pens, the percentage profit in selling a pen will be

The circumference of a circle is $6\pi\text{ cm}$. The length of an arc of the circle which subtends an angle of $\dfrac{1}{3}$ radian at the centre is

In the figure, $\angle A=75^\circ$, $\angle B=45^\circ$ and $CD$ bisects $\angle ACB$. $\dfrac{BD}{CD}=$

A rectangle is $6\text{ cm}$ long and $8\text{ cm}$ wide. The acute angle between its diagonals, correct to the nearest degree, is

In the figure, chords $AC$ and $BD$ meet at $E$ and $AB\parallel DC$. If $\angle CED=104^\circ$, find $\angle ABD$.

The real number $\pi$ is