In the trapezium $ABCD$, $AB$ is parallel to $CD$. $E$ and $F$ are points on $AD$ and $BC$ respectively such that $EF$ is also parallel to $AB$. The area, in cm$^2$, of triangles $BAF$, $CDF$ and $BCE$ are 8, 7 and 18 respectively. What is the area, in cm$^2$, of $ABCD$?
The radius of each wheel of Rick's bicycle is 25 cm. He rides to school at a constant speed and arrives after 10 minutes. During this time, each wheel makes 160 revolutions per minite. Of the following five distances, which is closest to that between Rick's home and school?
$ABC$ is an equilateral triangle. $D$ is a point inside such that $BCD$ is a right isosceles triangle. The altitude $BE$ of $ABC$ intersects $CD$ at $F$. What is the measure, in degrees, of $\angle CFE$?
Every student in a class is either in the mathematics club or the language club, and one third of them are in both. If there are 22 students in the language club, 4 less than the number of students in the mathematics club, how many students are there in this class?
The average of a group of numbers is 5. A second group contains twice as many numbers and its average is 11. What is the average when the two groups are combined?
Each of A and B goes to the gymnasium 3 or 4 times a week. After $n$ weeks, A has been there 57 times while B has been there only 47 times. What is the value of $n$?
With each vertex of a parallelogram $ABCD$ as centre, a circle is drawn. Exterior common tangents are then drawn, as shown in the diagram below. If the perimeter of $ABCD$ is 36 cm and the radius of each circle is 2 cm, what is the maximum area, in cm$^2$, of the figure enclosed by the circular arcs and tangents?