1980 年

The first term of an arithmetic progression is $6$ and its tenth term is three times its second term. The common difference is

A man sold a car for $\$35\,000$ at a loss of $30\%$ on the cost price. What would have been the loss or gain percent if he had sold it for $\$50\,500$?

If the length of a rectangle is increased by $10\%$ and the width decreased by $10\%$, which of the following is true?

The length of a side of a rhombus is $10\text{ cm}$. If its shorter diagonal is of length $12\text{ cm}$, what is the area of the rhombus in $\text{cm}^2$?

If the bearing of $B$ from $A$ is $\text{S}30^\circ\text{W}$, then the bearing of $A$ from $B$ is

$\dfrac{1}{\dfrac{1}{\sin\theta}-1}-\dfrac{1}{\dfrac{1}{\sin\theta}+1}=$

If $\cos\theta=x$ and $0^\circ<\theta<90^\circ$, then $\tan\theta=$

If $0^\circ\le\theta<360^\circ$, which of the following equations has exactly one root?

In the figure, $a:b:c=$

What is the area, in $\text{cm}^2$, of an equilateral triangle of side $x\text{ cm}$?