1985 年

A hawker bought 120 apples and the cost was $\$90$. It was found that $\dfrac{1}{8}$ of the apples were rotten and could not be sold. He sold the rest at $\$1$ each. What percentage of the cost was his profit?

The marked price of a book is double that of its cost. In a sale, what percentage discount was given if the profit made was $20\%$ of the cost?

John spends 40 minutes to walk from his home to school. If he increases his walking speed by $2\text{ km/h}$, then it takes only 30 minutes. What is the distance between John\'s home and his school?

$60\%$ of the students in a school are boys. $70\%$ of the boys and $40\%$ of the girls wear glasses. If 696 students wear glasses, how many students are there in the school?

In the figure, a regular hexagon of side $2\text{ cm}$ is inscribed in a circle. The area of the circle is greater than the area of the hexagon by

$\tan\theta\left(\dfrac{1}{\sin\theta}-\sin\theta\right)=$

If $\tan\theta=\dfrac{2ab}{a^2-b^2}$ and $0^\circ<\theta<90^\circ$, then $\cos\theta=$

In the figure, $AB=2$ and $AC=5$, $BC=$

In $\triangle ABC$, $\angle A=30^\circ$, $AB=6\text{ cm}$. If the area of $\triangle ABC$ is $15\text{ cm}^2$, $AC=$

In the figure, $BCE$ is a straight line. $AC=1$, $AB=$