1.  If a line segment is drawn connecting point A (6, 5) and point B (24, 21), then the coordinates of the midpoint are 

Hint
Halfnhalf Clue
 

2.  If the base of a triangle is decreased by 30%, and its height is increased by 30%, then the area of the triangle 
 Halfnhalf Clue
 

3.  A large water reservoir has two outlet pipes, a small one and a large one. It takes 7 hours to empty the reservoir when only the small outlet pipe is open. It takes 4 hours to empty the reservoir when only the large outlet pipe is open. About what fraction of the reservoir will be emptied in one hour if both the pipes are open? 
 Halfnhalf Clue
 

4.  Of the S students enrolled in a Programming Course, 80% take the Certification Examination. 40% of the students who take the Certification Examination pass it. In this Certification Examination, students who pass the examination are what percent of the students enrolled in the Programming Course? 
 Halfnhalf Clue
 
