The area of a trapezium is 121.5 cm2 and the distance between its parallel sides is 9 cm. If one of the parallel sides is of length 22 cm, find the length of the other side.
From a point in the interior of an equilateral triangle, perpendiculars are drawn on the three sides. If the lengths of the perpendiculars are a, b and c, find the area of the triangle.
In a class of 16 students, the average marks in a test was 63. If Yeeun got 62 marks and Jiwoo got 36 marks, what were the average of the other 14 students?
The number of boys in a class is four times the number of girls. Which one of the following numbers cannot represent the total number of children in the class?