What number must be added to each of the number 4, 6, 8, 11 in order to make them proportional ?

Using ruler and compass construct a triangle ABC in which AB = 6 cm. ∠BAC = 120° and AC = 5 cm. Construct a circle passing through A, B and C. Measure and write down the radius of the circle.

Which term of the Arithmetic Progression (A.P.) 15, 30, 45, 60 ….. is 300 ? Hence find the sum of all terms of the Arithmetic Progression (A.P.).

From the top of a tower 100 m high, a man observes the angle of depression of two ships A and B, on opposite sides of the tower as 45° and 38° respectively. If the foot of tower and the ships are in the same horizontal line, find the distance between two ships A and B to the nearest metre.