1. The ratio of two numbers is 3 : 4 and their HCF is 6. Their LCM is

(a) 36

(b) 72

(c) 108

(d) 144

2. Each interior angle of a regular polygon is 140°. the number of sides of the polygon is

(a) 7

(b) 8

(c) 9

(d) 10

3. There is a pyramid on a base which is a square of side 15 cm. If every slant edge of this pyramid is of length 20 cm, then the total surface area in sq. cm ofthis pyramid is

(a) 825

(b) 600

(c) 450

(d) 300

4. There is a pyramid on a base which is a square of side 15 cm. If height of this pyramid is of length 24 cm, then the volume (in cube cm) of this pyramid is

(a) 300

(b) 600

(c) 825

(d) 1000