Calculate the roots of the quadratic equation

One ticket is drawn at random from a bag containing tickets numbered 1 to 40. What is the probability that the selected ticket has a number which is a multiple of 5?

OR

A coin is tossed two times. Find the probability of getting atmost one head.

Calculate the value of the expression

OR

If sin – cos = 0, then calculate the value of (sin⁴ + cos⁴).

For the pair of equations and 2x + 6y + 14 = 0. What is the value of if the given pair of equations have infinitely many solutions?

In figure, two line segments AC and BD intersect each other at the point P such that PA = 6cm, PB = 3cm, PC = 2.5cm, PD = 5cm, ∠APB = 50° and ∠CDP = 30°.then, ∠PBA is equal to