For any real value of k, the roots of the quadratic equation x² + kx - 9 = 0 are :

1. real and equal

2. imaginary

3. real and unequal

4. none of these

Which term of the A.P. 18, 15, 12, ………… is the first negative term ?

1. 6^th

2. 8^th

3. 7^th

4. 5^th

In the given figure, BC = 16 cm, BD = 4 cm, then AB is equal to :

1. 5 cm

2. 8 cm

3. 6 cm

4. 4 cm

A thick card-board is cut into the shape as shown alongside. It is given a full round about its line of symmetry (shown by dotted line). The solid so formed has :

(i) one cone and one cylinder

(ii) two cones only

(iii) two cones and one cylinder

Which of the statements given above is true ?

1. only (i)

2. only (iii)

3. only (ii)

4. (ii) and (iii)