If an object moves in a purely rotatory motion, then each constituent particle of the body moves in a circle, the centre of which is located on a line is called _______.
X drives 30 km south, then turns right and drives 30km, then turns left and drives 20 km and then turns left and drives 30 km. How far is X from his/her initial position?
The mean score in a test of the 10 boys in a class was 15 while the overall mean of the 25 students in the class was 16.2. What was the mean score of the girls?