The volume of a conical tent is 462 m³ and the area of the base 154 m². The height of the conical tent is :

1. 15m

2. 12 m

3. 9 m

4. 24 m

The radius of a roller 100 cm long is 14 cm. The curved surface area of the roller is

1. 13200 m²

2. 15400 m²

3. 4400 m²

4. 8800 m²

The radii of two cylinders are in the ratio 2 : 3 and their heights are in the ratio 5 : 3. The ratio of their volumes is

1. 10 : 17

2. 20 : 27

3. 17 : 27

4. 20 : 37

The total surface area of a cone whose radius is $\dfrac{r}{2}$ and slant height 2l is

1. 2πr(l + r)

2. $πr \Big(l + \dfrac{r}{4}\Big)$

3. πr(l + r)

4. 2πrl