The co-ordinates of the centroid of a triangle ABC are (1 , -4). What are the co-ordinates of vertex C if co-ordinates of A and B are (3 , -4) and (0 , 5) respectively?
The mean score in a test of the 12 boys in a class was 16 while the overall mean of the 30 students in the class was 18.1. What was the mean score of the girls?