00:00:55 Meaning and derivation of rule for Sum to n terms of an AP

00:15:47 Difference between general term and sum to n terms of an AP

00:17:34 NCERT Exercise 5.3 Question 1

00:26:14 NCERT Exercise 5.3 Question 2

00:36:54 NCERT Exercise 5.3 Question 3 part (i) (ii) (iii)