Question

The slant height of a bucket is 45 cm and the radii of its top and bottom are 28 cm and 7 cm, respectively. The curved surface area of the bucket is
(a) 4953 cm²
(b) 4952 cm²
(c) 4951 cm²
(d) 4950 cm²

Answer 1

(d) 4950 cm²
Let the radii of the top and bottom of the bucket be R and r and let its slant height be l.
Then, $R=28\text{cm},r=7\text{cm},l=45\text{cm}$
Curved surface area of the bucket$=\mathrm{\pi }l\left(R+r\right)$
$$\begin{gathered} =\frac{22}{7}\times 45\times \left(28+7\right){\text{cm}}^2 \\ =4950{\text{cm}}^2 \end{gathered}$$

Hence, the curved surface area of the bucket is 4950 cm².