Please Solve R.D. Sharma class 12 Chapter 22 Algbra of Vectors Exercise Very Short Answer Question 10 Maths textbook Solution.
Answer: 
Hint: You must know the rules of vector functions
Given: If are position vectors of vertices of a triangle, then write the position vector of centroid.
Solution: Let ABC be a triangle and D,E and F are the mid-points of sides BC, CA and AB respectively.
Also, Let are position vectors of A, B, C respectively.                          
Then position vectors of D, E and F are
                 respectively.                                                            
The position vector of a point divides AD in the ratio of 2 is                                         
Similarly, position vectors of the points divides BE, CF in the ratio of 2:1 are equal to
            
Thus, the points dividing AD in ratio 2:1 also divides BE, CF in the ratio.
Hence, medians of triangle are concurrent and the position of centroid is