14.At Kilamara secondary school, the distance (d1) from the dormitories to the classrooms is twice the distance (d2) from the classroom to the playing grounds whereas the distance (d3) from the dormitories to the playing grounds is three times the distance from the dormitories to the classrooms. Using the given notations write down the two equations that summarizes this information and hence find the equation that connects d3 and d2 .
19.If a triangle has two equal sides of length x cm each and the length of the remaining side is one quarter of the total length of the two congruent sides, write down an equation that represents the perimeter of this triangle.
24.In a class of 45 students, some study physics or chemistry or both. If 23 students study physics, 33 study chemistry and 10 students do not study neither physics nor chemistry, find the number of students who study both physics and chemistry using the formula.