Class 10 Math dose part 3

1. Solve the given equation by the method of completing the squares: x²+ 12x – 45 = 0

2. The sum of first six terms of an A.P. is 42. The ratio of its 10th term to its 30th term is 1:3. Find the first term of the A.P.

3. From the top of a lighthouse 75 m high, the angles of depression of two ships are observed to be  30^o and 45^o respectively. If one ship is directly behind the other on the same side of the lighthouse then find the distance between the two ships.

4. Find the area of the minor segment of a circle of radius 42cm, if the length of the corresponding  arc is 44 cm.

5. A train covers a distance of 90 kms at a uniform speed. It would have taken 30 minutes less if the speed had been 15 km/hr more. Calculate the original duration of the journey