A lot consists of 144 ball pens of which 20 are defective. The customer will buy a ball pen if it is good but will not buy a defective ball pen. The shopkeeper draws one pen at random from the lot and gives it to the customer. What is the probability that?

(i) customer will buy the ball pen

(ii) customer will not buy the ball pen

A wire when bent in the form of an equilateral triangle encloses an area of 121√3 cm². If the wire is bent in the form of a circle, find the area enclosed by the circle (use ).

Find the area of the triangle formed by joining the mid-points of the sides of a triangle, whose coordinates of vertices are (0, –1), (2, 1) and (0, 3).

Water in a canal 6 m wide and 1.5 m deep, is flowing with a speed of 10 km/h. How much area will it irrigate in 30 minutes, if 8 cm of standing water is needed for irrigation?

In Fig. 4, ABCD is a trapezium with AB || DC and BCD = 30°. If BGEC is a sector of a circle with center C and AB = BC = 7 cm, DE = 4 cm and BF = 3.5 cm, then find the area of the shaded region (use ).

(Fig. 4)