Prove that

OR

Prove that

The nth term of an AP is (7 – 4n), then what is its common difference?

A bag contains 5 red balls and some blue balls. If the probability of drawing a blue ball at random from the bag is three times that of a red ball, find the number of blue balls in the bag.

Two different dice are thrown together, find the probability that the sum of the numbers appeared is less than 5.

OR

Find the probability that 5 Sundays occur in the month of November of a randomly selected year.

In Fig. 4, a circle touches all the four sides of a quadrilateral ABCD. If AB = 6 cm, BC = 9cm, and CD = 8 cm, then find the length of AD.