This video lecture from Permutation, Combination and Probability (F.Sc. first year Mathematics) covers: Question numbers 1-3 of exercise 7.2. In these questions we evaluate the given permutations and prove the given equations using first principle of permutation. Find more e-learning material and educational video lectures in Urdu at maktab.pk. These videos are free to use for promotional and commercial purpose by keeping the credits to Maktab.